Filed Pursuant to Rule 424(b)(5)
Registration Statement No. 333-255845

PROSPECTUS SUPPLEMENT

(to Prospectus dated May 6, 2021)

$40,000,000

POTBELLY CORPORATION

COMMON STOCK

We have entered into an equity sales agreement, or the “sales agreement,” with William Blair & Company, L.L.C., or the “Agent,” relating to our common stock offered by this prospectus supplement. In accordance with the terms of the sales agreement, we may offer and sell our common stock, having an aggregate offering price of up to $40,000,000 from time to time through the Agent.

Our common stock is listed on the Nasdaq Global Select Market under the symbol “PBPB.” On November 2, 2021, the closing price of our common stock as reported by the Nasdaq Global Select Market was $6.09 per share.

Sales of our common stock, if any, under this prospectus supplement and the accompanying prospectus may be made in sales deemed to be an “at the market offering” as defined in Rule 415 promulgated under the Securities Act of 1933, as amended, or the “Securities Act”, through or to the Agent as agent or/and principal. The Agent will act as a sales agent on a best efforts basis using commercially reasonable efforts consistent with its normal trading and sales practices, on mutually agreed terms between the Agent and us. There is no arrangement for funds to be received in any escrow, trust or similar arrangement.

The compensation to the Agent for sales of common stock sold pursuant to the sales agreement is up to 3.0% of the gross proceeds from the sales. In connection with the sale of the common stock on our behalf, the Agent will be deemed to be an “underwriter” within the meaning of the Securities Act and the compensation of the Agent will be deemed to be underwriting commissions or discounts. We have also agreed to provide indemnification and contribution to the Agent with respect to certain liabilities, including liabilities under the Securities Act.

An investment in our common stock involves a high degree of risk. See “Risk Factors ” beginning on page S-3 of this prospectus supplement, and under similar headings in other documents that are filed after the date hereof and incorporated by reference into this prospectus supplement, for more information on these risks.

NEITHER THE SECURITIES AND EXCHANGE COMMISSION NOR ANY STATE SECURITIES COMMISSION HAS APPROVED OR DISAPPROVED OF THESE SECURITIES OR PASSED UPON THE ADEQUACY OR ACCURACY OF THIS PROSPECTUS SUPPLEMENT. ANY REPRESENTATION TO THE CONTRARY IS A CRIMINAL OFFENSE.

WILLIAM BLAIR

Prospectus Supplement dated November 3, 2021

TABLE OF CONTENTS

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ABOUT THIS PROSPECTUS SUPPLEMENT AND THE ACCOMPANYING PROSPECTUS

This document consists of two parts and is part of a registration statement on Form S-3 that we filed with the Securities and Exchange Commission (the “SEC”) utilizing a “shelf” registration process. The first part is this prospectus supplement, which describes the specific terms of this offering and also adds to and updates the information contained in the accompanying prospectus and the documents incorporated by reference into this prospectus supplement and the accompanying prospectus. The second part, the accompanying prospectus, gives more general information, some of which may not apply to this offering. If there is a difference between the information contained in this prospectus supplement, on the one hand, and the information contained in the accompanying prospectus or any document incorporated by reference, on the other hand, you should rely on the information in this prospectus supplement. Generally, when we refer to the prospectus, we are referring to this prospectus supplement and the accompanying prospectus combined.

Before you invest in shares of our common stock, you should read this prospectus supplement and the accompanying prospectus and any related issuer free writing prospectus, as well as the additional information incorporated by reference in this prospectus supplement described below under “Where You Can Find More Information” and “Information Incorporated by Reference” or in any related issuer free writing prospectus.

This prospectus supplement contains summaries of certain provisions contained in some of the documents described herein, but reference is made to the actual documents for complete information. All of the summaries are qualified in their entirety by the actual documents. Copies of the documents referred to herein have been filed, or will be filed or incorporated by reference as exhibits to the registration statement of which this prospectus supplement is a part, and you may obtain copies of those documents as described below under “Where You Can Find More Information.”

Neither the delivery of this prospectus supplement, the accompanying prospectus or any free writing prospectus prepared by us, nor any sale made under this prospectus supplement, the accompanying prospectus or any free writing prospectus prepared by us, implies that there has been no change in our affairs or that the information therein is correct as of any date after the date of such document. You should not assume that the information in this prospectus supplement or the accompanying prospectus, including any information incorporated in this prospectus supplement or the accompanying prospectus by reference, or any free writing prospectus prepared by us, is accurate as of any date other than the date on the front of those documents. Our business, financial condition, results of operations and prospects may have changed since that date.

Any statement made in this prospectus supplement or in a document incorporated or deemed to be incorporated by reference therein will be deemed to be modified or superseded for purposes of this prospectus supplement to the extent that a statement contained in this prospectus supplement or in any other subsequently filed document that is also incorporated or deemed to be incorporated by reference in this prospectus supplement modifies or supersedes that statement. Any statement so modified or superseded will not be deemed, except as so modified or superseded, to constitute a part of this prospectus supplement.

We are responsible for the information contained in or incorporated by reference in this prospectus supplement, the accompanying prospectus and any related issuer free writing prospectus we have authorized for use in connection with this offering. This prospectus supplement may be used only for the purpose for which it has been prepared. You may rely only on the information contained or incorporated by reference in this prospectus supplement. Neither we nor any other person has authorized anyone to provide information different from the information contained in this prospectus supplement, the accompanying prospectus and any related issuer free writing prospectus and the documents incorporated by reference herein and therein.

You should not consider any information included or incorporated by reference in this prospectus supplement or the accompanying prospectus to be legal, tax or investment advice. You should consult your own counsel,

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accountant and other advisors for legal, tax, business, financial and related advice regarding any purchase of our securities. Neither we nor the Agent makes any representation regarding the legality of an investment in our common stock by any person under applicable investment or similar laws.

We are not making an offer to sell our common stock in any jurisdiction where the offer or sale is not permitted. This prospectus supplement does not constitute an offer or an invitation to subscribe for and purchase any of our securities, and may not be used for or in connection with an offer or solicitation by any person, in any jurisdiction in which such an offer or solicitation is not authorized or to any person to whom it is unlawful to make such an offer or solicitation. This prospectus supplement does not contain all of the information included in the registration statement. For a more complete understanding of the offering of the securities, you should refer to the registration statement, including its exhibits.

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RISK FACTORS

Our business is subject to significant risks. Before you invest in our common stock, you should carefully consider, among other matters, the risks and uncertainties described below, as well as the other information contained or incorporated by reference in this prospectus, including our consolidated financial statements and accompanying notes and the information under the heading “Risk Factors” in our most recent annual report on Form 10-K and quarterly reports on Form 10-Q. See “Information Incorporated by Reference” beginning on page S-11. If any of the risks and uncertainties described in this prospectus or the documents incorporated by reference herein actually occur, our business, financial condition, or results of operations could be materially adversely affected. This could cause the market or trading price of our common stock to decline, perhaps significantly, and you may lose part or all of your investment. Please note that additional risks not presently known to us or that we currently deem immaterial may also impair our business, financial condition and operations.

Risks Relating to this Offering

If you purchase our common stock in the offering, you will experience immediate dilution in your investment and you will experience further dilution if we issue additional equity or convertible debt securities in future offerings.

Since the public offering price per share of our common stock is substantially higher than the net tangible book value per share of our common stock, you will suffer immediate and substantial dilution in the net tangible book value of the common stock you purchase in the offering.

In addition, the exercise of any of our outstanding options or warrants or settlement of our outstanding restricted stock units or performance stock units could result in additional dilution.

We may also choose to raise additional capital from time to time, even if we believe we have sufficient funds for our current or future operating plans. To the extent that we raise additional funds through the sale of equity or convertible debt securities, the issuance of such securities will result in dilution to our stockholders. Investors purchasing shares or other securities in the future could have rights superior to existing stockholders. The price per share at which we sell additional shares of our common stock, or securities convertible or exchangeable into common stock, in future transactions may be higher or lower than the price per share paid by investors in the offering.

You will experience immediate dilution in the book value per share of the common stock you purchase in this offering.

Because the price per share of our common stock being offered is substantially higher than the book value per share of our common stock, you will suffer substantial dilution in the net tangible book value of the common stock you purchase in this offering. Based on the assumed public offering price of $6.09 per share (the closing sale price of our common stock on the Nasdaq Global Select Market on November 2, 2021) and assuming that we sell all $40,000,000 of shares of common stock under this prospectus, and after deducting commissions and estimated aggregate offering expenses payable by us, if you purchase shares of common stock in this offering, you will suffer immediate and substantial dilution of $5.07 per share in the net tangible book value of the common stock. See the section titled “Dilution” below for a more detailed discussion of the dilution you will incur if you purchase common stock in this offering.

Our management will have broad discretion over the use of the proceeds from this offering and might not apply the proceeds of this offering in ways that increase the value of your investment.

We currently intend to use the net proceeds from this offering for working capital and general corporate purposes. See “Use of Proceeds” of this prospectus supplement. However, our management will have broad

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discretion over the use of the net proceeds from this offering, and you will be relying on the judgment of our management regarding the application of these proceeds. They might not apply the net proceeds of this offering in ways that increase the value of your investment. The amounts and timing of our actual expenditures will depend on numerous factors, including the factors described under “Risk Factors” in this prospectus supplement and in the documents incorporated by reference herein, as well as the amount of cash used in our operations. We may find it necessary or advisable to use the net proceeds for other purposes, and our management will have significant flexibility in applying the net proceeds of this offering.

It is not possible to predict the aggregate proceeds resulting from sales made under the sales agreement.

Subject to certain limitations in the sales agreement and compliance with applicable law, we have the discretion to deliver a placement notice to the Agent at any time throughout the term of the sales agreement. The number of shares that are sold through the Agent after delivering a placement notice will fluctuate based on a number of factors, including the market price of our common stock during the sales period, the limits we set with the Agent in any applicable placement notice, and the demand for our common stock during the sales period. Because the price per share of each share sold will fluctuate during the sales period, it is not currently possible to predict the aggregate proceeds to be raised in connection with those sales.

The common stock offered hereby will be sold in “at the market offerings,” and investors who buy shares at different times will likely pay different prices.

Investors who purchase shares in this offering at different times will likely pay different prices, and so may experience different levels of dilution and different outcomes in their investment results. We will have discretion, subject to market demand, to vary the timing, prices, and number of shares sold in this offering. In addition, subject to the final determination by our Board of Directors, there is no minimum or maximum sales price for shares to be sold in this offering. Investors may experience a decline in the value of the shares they purchase in this offering as a result of sales made at prices lower than the prices they paid.

Future sales of our common stock or equity-linked securities in the public market could lower the market price of our common stock.

In the future, we may sell additional shares of our common stock or equity-linked securities to raise capital. In addition, a substantial number of shares of our common stock are reserved for issuance upon the exercise or vesting, as applicable, of equity incentive awards and warrants. We cannot predict the size of future issuances or the effect, if any, that they may have on the market price of our common stock. The issuance and sale of substantial amounts of common stock or equity-linked securities, or the perception that such issuances and sales may occur, could adversely affect the market price of our common stock and impair our ability to raise capital through the sale of additional equity or equity-linked securities.

The volatility of our stock price could adversely affect current and future stockholders.

The market price of our common stock is volatile and fluctuates in response to various factors which are beyond our control. The following factors, in addition to other risk factors described in this section, could cause the market price of our common stock to fluctuate substantially:

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In addition, the stock markets, from time to time, experience extreme price and volume fluctuations that may be unrelated or disproportionate to the operating performance of companies. These broad fluctuations may adversely affect the market price of our common stock. Price volatility could be worse if the trading volume of our common stock is low.

Because we have no plans to pay regular cash dividends on our common stock for the foreseeable future, you may not receive any return on investment unless you sell your common stock for a price greater than that which you paid for it.

We may retain future earnings, if any, for future operations, expansion and debt repayment and have no current plans to pay any cash dividends for the foreseeable future. Any decision to declare and pay dividends in the future will be made at the discretion of our board of directors and will depend on, among other things, our results of operations, financial condition, cash requirements, contractual restrictions and other factors that our board of directors may deem relevant. In addition, our ability to pay dividends may be limited by covenants of any existing and future outstanding indebtedness we or our subsidiaries incur, including our credit facility. As a result, you may not receive any return on an investment in our common stock unless you sell our common stock for a price greater than that which you paid for it.

SPECIAL NOTE REGARDING FORWARD-LOOKING STATEMENTS

Information presented in this prospectus supplement, the accompanying prospectus and any free writing prospectus prepared by or on behalf of us or to which we have referred you, and in other documents which are incorporated by reference in this prospectus supplement under the sections of this prospectus supplement entitled “Where You Can Find More Information” and “Information Incorporated by Reference,” that discusses financial projections, information or expectations about our business plans, results of operations, products or markets, or otherwise makes statements about future events, are forward-looking statements. Forward-looking statements can be identified by the use of words such as “intends,” “anticipates,” “believes,” “estimates,” “projects,” “forecasts,” “expects,” “plans,” and “proposes.” Although we believe that the expectations reflected in these forward-looking statements are based on reasonable assumptions, there are a number of risks and uncertainties that could cause

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actual results to differ materially from these forward-looking statements. By their nature, forward-looking statements involve risks and uncertainties because they relate to events and depend on circumstances that may or may not occur in the future. We believe that these risks and uncertainties include, but are not limited to, those described in the “Risk Factors” section of this prospectus supplement, which include, but are not limited to, the following:

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These cautionary statements identify important factors that could cause actual results to differ materially from those described in the forward-looking statements. When considering forward-looking statements in this prospectus supplement, you should keep in mind the cautionary statements in the “Risk Factors” section and other sections of this prospectus supplement and other cautionary statements in the accompanying prospectus and any free writing prospectus prepared by or on behalf of us or to which we have referred you and any documents which are incorporated by reference in this prospectus supplement and listed in “Where You Can Find More Information” and “Information Incorporated by Reference” beginning on pages S-10 and S-11, respectively.

Certain risks, uncertainties, and other factors are incorporated herein by reference to our most recent Annual Report on Form 10-K and our subsequent Quarterly Reports on Form 10-Q, along with the other information contained in this prospectus supplement, as updated by our subsequent filings under the Securities Exchange Act of 1934, as amended, or the “Exchange Act.” Except as otherwise required by applicable securities laws, we undertake no obligation to publicly update or revise any forward-looking statements, whether as a result of new information, future events, changed circumstances, or any other reason, after the date of this prospectus supplement.

USE OF PROCEEDS

We may issue and sell shares of our common stock having aggregate sales proceeds of up to $40,000,000 from time to time. Because there is no minimum offering amount required as a condition to close this offering, the actual total public offering amount, commissions and proceeds to us, if any, are not determinable at this time. There can be no assurance that we will sell any shares under or fully utilize the sales agreement with the Agent as a source of financing.

We currently intend to use the net proceeds from this offering for working capital and general corporate purposes. We may find it necessary or advisable to use the net proceeds for other purposes, and our management will have significant flexibility in applying the net proceeds of this offering.

DIVIDEND POLICY

We do not anticipate paying any cash dividends on shares of our common stock in the foreseeable future. We currently intend to retain all of our future earnings, if any, to finance our business strategy. Any future determination relating to our dividend policy will be made at the discretion of our Board of Directors and will depend on a number of factors, including future earnings, capital requirements, financial conditions, future prospects, contractual restrictions and covenants and other factors that our Board of Directors may deem relevant.

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DILUTION

If you invest in our common stock in this offering, your ownership interest will be diluted to the extent of the difference between the public offering price per share and our pro forma net tangible book value per share after this offering. We calculate net tangible book value per share by dividing our net tangible book value, which is tangible assets less total liabilities, by the number of outstanding shares of our common stock.

Our net tangible book value as of June 27, 2021 was approximately $(3.1) million, or $(0.11) per share. After giving effect to the sale by us of 6,568,144 shares of common stock offered hereby at the assumed public offering price of $6.09 per share (the closing sale price of our common stock on the Nasdaq Global Select Market on November 2, 2021) and after deducting the sales agent commission and estimated offering expenses payable by us, our pro forma as adjusted net tangible book value as of June 27, 2021 would have been approximately $35.5 million, or $1.02 per share. This represents an immediate increase in as adjusted net tangible book value of $1.13 per share to existing stockholders and an immediate dilution of $5.07 per share to new investors purchasing our common stock in this offering. The following table illustrates the per share dilution to investors purchasing shares of common stock in this offering:

The table above assumes for illustrative purposes that an aggregate of 6,568,144 shares of our common stock are sold during the term of the sales agreement at a price of $6.09 per share (the closing sale price of our common stock on the Nasdaq Global Select Market on November 2, 2021), for aggregate gross proceeds of approximately $40,000,000. The shares sold in this offering, if any, will be sold from time to time at various prices.

The information discussed above is illustrative only and will adjust based on the actual public offering price and other terms of this offering determined at each sale under the sales agreement.

The above table is based on 28,170,835 shares of common stock issued and outstanding as of June 27, 2021, and does not include, as of June 27, 2021:

To the extent that the outstanding options or warrants are exercised, or shares are issued upon the vesting of restricted stock units or performance stock units, you will experience further dilution. To the extent that the above issued options and warrants are exercised, or shares are issued upon the vesting of restricted stock units or performance stock units, the pro forma net tangible book value per share of our common stock after giving effect to this offering would be $0.84 per share, and the dilution in net tangible book value per share to purchasers in this offering would be $5.25 per share. In addition, we may choose to raise additional capital due to market conditions or strategic considerations. To the extent that additional capital is raised through the sale of securities, the issuance of those securities could result in further dilution to our stockholders.

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PLAN OF DISTRIBUTION

We have entered into an equity sales agreement, dated November 3, 2021, with the Agent under which we may issue and sell from time to time shares of our common stock having an aggregate offering price of up to $40,000,000 through the Agent. This summary of the material provisions of the sales agreement does not purport to be a complete statement of its terms and conditions. This summary is qualified in its entirety by reference to the sales agreement, which has been filed with the SEC.

Upon delivery of a placement notice, and subject to our instructions in such placement notice and the terms and conditions of the sales agreement, the Agent may sell our common stock by any method that is deemed to be an “at the market” offering as defined in Rule 415 under the Securities Act. We may instruct the Agent not to sell our common stock if the sales cannot be effected at or above the price designated by us from time to time.

We will pay the Agent, in cash, upon each sale of our common stock pursuant to the sales agreement, a commission in an amount equal to 3.0% of the aggregate gross proceeds from such sale. We have also agreed to reimburse the Agent up to $50,000 for the Agent’s reasonable and documented expenses incurred in connection with this offering. Because there is no minimum offering amount required as a condition to this offering, the actual total public offering amount, commissions and proceeds to us, if any, are not determinable at this time.

Settlement for sales of common stock will occur on the second business day that is also a trading day following the date on which any sales are made, or on some other date that is agreed upon by us and the Agent in connection with a particular transaction, in return for payment of the net proceeds to us. There is no arrangement for funds to be received in an escrow, trust or similar arrangement. Sales of our common stock as contemplated this prospectus supplement will be settled through the facilities of The Depository Trust Company or by such other means as we and the Agent may agree upon.

The Agent will act as sales agent using commercially reasonable efforts, consistent with its normal trading and sales practices and applicable state and federal laws, rules and regulations and the rules of The Nasdaq Global Select Market. In connection with the sales of the common stock on our behalf, the Agent will be deemed to be an “underwriter” within the meaning of the Securities Act, and the compensation paid to the Agent will be deemed to be underwriting commissions or discounts. We have agreed to provide indemnification and contribution to the Agent against certain liabilities, including liabilities under the Securities Act.

The offering of our common stock pursuant to the sales agreement will terminate as permitted therein. We or the Agent may terminate the sales agreement at any time upon five days’ prior notice.

The Agent and its affiliates have provided, and may in the future provide, various investment banking, commercial banking and other financial services for us and our affiliates, for which services they have received, and may in the future receive, customary fees. To the extent required by Regulation M, the Agent will not engage in any market making activities involving our common stock while the offering is ongoing under this prospectus supplement.

This prospectus supplement in electronic format may be made available on a website maintained by the Agent, and the Agent may distribute this prospectus supplement electronically.

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LEGAL MATTERS

The validity of the securities offered hereby will be passed upon for us by Greenberg Traurig, P.A., Fort Lauderdale, Florida. William Blair  & Company, L.L.C. is being represented in connection with this offering by DLA Piper LLP (US), New York, New York.

EXPERTS

The financial statements of Potbelly Corporation for the year ended December 27, 2020, incorporated by reference in this Prospectus, have been audited by Deloitte & Touche LLP, an independent registered public accounting firm, as stated in their report. Such financial statements are incorporated by reference in reliance upon the report of such firm, given their authority as experts in accounting and auditing.

WHERE YOU CAN FIND MORE INFORMATION

We file quarterly and annual reports, proxy statements and other information with the SEC. Our filings with the SEC, including the registration statement, reports, proxy and information statements, and other information are available to you on the SEC’s website at http://www.sec.gov. In addition, documents that we file with the SEC are available on our website at www.potbelly.com. Our website address provided in this prospectus is not intended to function as a hyperlink and the information on our website is not, nor should it be considered, part of this prospectus or incorporated by reference into this prospectus.

This prospectus supplement is part of a registration statement that we have filed with the SEC relating to the securities offered herein. This prospectus supplement does not contain all of the information we have included in the registration statement and the accompanying exhibits and schedules in accordance with the rules and regulations of the SEC, and we refer you to the omitted information. The statements this prospectus supplement makes pertaining to the content of any contract, agreement or other document that is an exhibit to the registration statement necessarily are summaries of their material provisions and do not describe all exceptions and qualifications contained in those contracts, agreements or documents. You should read those contracts, agreements or documents for information that may be important to you. The registration statement, exhibits and schedules are available at the SEC’s Internet website.

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INFORMATION INCORPORATED BY REFERENCE

The rules of the SEC allow us to incorporate by reference in this prospectus supplement the information in other documents that we file with it, which means that we can disclose important information to you by referring you to those documents that we have filed separately with the SEC. You should read the information incorporated by reference because it is an important part of this prospectus supplement. We hereby incorporate by reference the following information or documents into this prospectus supplement:

Any information in any of the foregoing documents will automatically be deemed to be modified or superseded to the extent that information in this prospectus or in a later filed document that is incorporated or deemed to be incorporated herein by reference modifies or replaces such information.

We also incorporate by reference any future filings (other than current reports furnished under Item 2.02 or Item 7.01 of Form 8-K and exhibits filed on such form that are related to such items) made with the SEC pursuant to Sections 13(a), 13(c), 14 or 15(d) of the Exchange Act, until the termination of the offering as to which this prospectus supplement relates. Information in such future filings updates and supplements the information provided in this prospectus supplement and the accompanying prospectus. Any statements in any such future filings will automatically be deemed to modify and supersede any information in any document we previously filed with the SEC that is incorporated or deemed to be incorporated herein by reference to the extent that statements in the later filed document modify or replace such earlier statements.

You may obtain a copy of these filings, without charge, by writing or calling us at:

Potbelly Corporation

111 North Canal Street

Suite 325

Chicago, Illinois 60606

(312) 951-0600

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PRELIMINARY PROSPECTUS

$75,000,000

POTBELLY CORPORATION

COMMON STOCK

PREFERRED STOCK

DEBT SECURITIES

WARRANTS

UNITS

We may offer, issue and sell, from time to time, in one or more offerings and series, together or separately, shares of our common stock, shares of our preferred stock, debt securities, warrants or units, in amounts, at prices and on terms that will be determined at the time of any such offering and described in one or more supplements to this prospectus. The debt securities and preferred stock we may offer may be convertible into or exercisable or exchangeable for debt, common or preferred stock or other securities of Potbelly Corporation or debt or equity securities of one or more other entities.

This prospectus provides a general description of the securities that we may offer and the general manner in which we will offer them. Each time we offer securities for sale using this prospectus, we will provide specific terms and describe the specific manner in which we will offer these securities in supplements to this prospectus. The prospectus supplement may also add, update or change the information in this prospectus.

This prospectus may not be used to offer or sell securities unless accompanied by a prospectus supplement that includes a description of the method and terms of the offering.

You should carefully read this prospectus and any accompanying prospectus supplement, together with the documents we incorporate herein by reference, before you invest in our securities. If there is any inconsistency between the information in this prospectus and any prospectus supplement, you should rely on the information in the prospectus supplement.

Our common stock is listed on the Nasdaq Global Select Market (the “Nasdaq”) under the ticker symbol “PBPB.”

Investing in our securities involves risks. Please refer to the “Risk Factors” section on page 4 and the supplemental risk factors contained in any applicable prospectus supplement and in the documents we incorporate herein by reference for a description of the risks you should consider before making an investment decision.

Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of these securities or determined if this prospectus is truthful or complete. Any representation to the contrary is a criminal offense.

The date of this prospectus is May 13, 2021.

TABLE OF CONTENTS

ABOUT THIS PROSPECTUS

This prospectus is part of a “shelf” registration statement that we have filed with the Securities and Exchange Commission (the “SEC”).

Under this shelf registration process, we may, from time to time, offer and/or sell, in one or more offerings and series, together or separately, shares of our common stock, preferred stock, debt securities, warrants or units. This prospectus only provides you with a general description of the securities that we may offer. Each time we offer and sell our securities under this prospectus, we will provide a prospectus supplement and attach it to this prospectus. The prospectus supplement will contain more specific information about the terms of the securities and the offering. The prospectus supplement may also add, update or change information contained in this prospectus. Any statement that we make in this prospectus will be modified or superseded by any inconsistent statement made by us in a prospectus supplement. Before purchasing any of our securities, you should read both this prospectus and any accompanying prospectus supplement together with the additional information described under the heading “Where You Can Find More Information.”

You should rely only on the information contained in this prospectus, the documents incorporated by reference in this prospectus and any prospectus supplement that we may provide to you. We have not authorized anyone to provide you with information different from that contained in this prospectus or any prospectus supplement. If anyone provides you with different or additional information, you should not rely on it. This prospectus may only be used where it is legal to sell these securities. This prospectus is not an offer to sell, or a solicitation of an offer to buy, in any state where the offer or sale is prohibited. The information in this prospectus, any prospectus supplement or any documents incorporated herein or therein by reference is accurate as of the date contained on the cover of such documents. Neither the delivery of this prospectus or any prospectus supplement, nor any sale made under this prospectus or any prospectus supplement will, under any circumstances, imply that the information in this prospectus or any prospectus supplement is correct as of any date after the date of this prospectus or any such prospectus supplement.

Unless indicated otherwise, references in this prospectus to “Potbelly,” the “Company,” “we,” “us” and “our” refer to Potbelly Corporation and its subsidiaries.

FORWARD-LOOKING STATEMENTS

This prospectus and the documents incorporated herein by reference contain “forward-looking statements” within the meaning of Section 27A of the Securities Act of 1933, as amended (the “Securities Act”), and Section 21E of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), are made throughout this prospectus and are intended to come within the safe harbor protection provided by those sections. These forward-looking statements can generally be identified by the use of forward-looking terminology, including the terms “believes,” “estimates,” “anticipates,” “expects,” “strives,” “goal,” “seeks,” “projects,” “intends,” “forecasts,” “plans,” “may,” “will” or “should” or, in each case, their negative or other variations or comparable terminology. They appear in a number of places throughout this Annual Report and include statements regarding our intentions, beliefs or current expectations concerning, among other things, our results of operations, financial condition, liquidity, prospects, growth, strategies and the industry in which we operate.

By their nature, forward-looking statements involve risks and uncertainties because they relate to events and depend on circumstances that may or may not occur in the future. We believe that these risks and uncertainties include, but are not limited to, those described in the section of this prospectus titled “Risk Factors” and elsewhere in this prospectus and in other documents incorporated herein or therein (including in our most recent annual report on Form 10-K), which include, but are not limited to, the following:

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These factors should not be construed as exhaustive and should be read in conjunction with the other cautionary statements included in this document. These risks and uncertainties, as well as other risks of which we are not aware or which we currently do not believe to be material, may cause our actual future results to be materially different than those expressed in our forward-looking statements. We do not undertake to update our forward-looking statements, whether as a result of new information, future events or otherwise, except as may be required by law.

You should read this prospectus completely and with the understanding that our actual future results, levels of activity, performance and achievements may be different from what we expect and that these differences may be material. We qualify all of our forward-looking statements by these cautionary statements.

POTBELLY CORPORATION

Potbelly Corporation is a sandwich concept that has been feeding customers’ smiles with warm, toasty sandwiches, signature salads, hand-dipped shakes and other fresh menu items, customized just the way customers want them, for more than 40 years. Potbelly promises Fresh, Fast & Friendly service in an environment that reflects the local neighborhood. Our employees are trained to engage with our customers in a genuine way to provide a personalized experience. We believe the combination of our great food, people and atmosphere allows Potbelly to help people love lunch and creates a devoted base of Potbelly fans.

We believe that a key to our past and future success is our culture. It is embodied in The Potbelly Advantage, which is an expression of our Vision, Mission and Values, and the foundation of everything we do. Our Vision is to be your moment of escape, thanks to our relaxing shop, friendly faces, and toasty sandwiches. Our Mission is to help people love lunch. Our Values embody both how we lead and how we behave, and form the cornerstone of our culture. We use simple language that resonates from the frontline associate to the most senior levels of the organization, creating shared expectations and accountabilities in how we approach our day-to-day activities. We strive to be a fun, friendly and hardworking group of people who enjoy taking care of our customers, while at the same time taking care of each other.

As of December 27, 2020, we had 446 shops in 32 states and the District of Columbia. Of these, the Company operated 400 shops and franchisees operated 46 shops.

We were incorporated in Delaware in June 2001 as Potbelly Sandwich Works, Inc. and changed our name to Potbelly Corporation in 2002. Our principal offices are located at 111 North Canal Street, Suite 325, Chicago, Illinois 60606 and our telephone number is (312) 951-0600. We maintain a website with the address www.potbelly.com. The contents of our website are not incorporated by reference into this prospectus.

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RISK FACTORS

An investment in our securities involves risks. You should consider carefully the risks and uncertainties described under the heading “Risk Factors” in any applicable prospectus supplement and under the caption “Risk Factors” in any of our filings with the SEC pursuant to Sections 13(a), 13(c), 14 or 15(d) of the Exchange Act, which are incorporated herein by reference, before you decide whether to purchase any of our securities. These risks could materially adversely affect our business, financial condition, results of operations and cash flows, and you may lose part or all of your investment. For more information, see the section of this prospectus titled “Where You Can Find More Information.”

USE OF PROCEEDS

Unless stated otherwise in a prospectus supplement, the net proceeds from the sale of securities described in this prospectus will be used for general corporate purposes.

DESCRIPTION OF CAPITAL STOCK

The following is a description of certain general terms and provisions of our common stock and preferred stock. This description does not purport to be complete and is subject in all respects to applicable Delaware law and qualified by reference to the provisions of our certificate of incorporation and our bylaws. Copies of our certificate of incorporation and bylaws are incorporated by reference herein and will be provided to stockholders upon request. See “Where Can You Find More Information.”

General

The Company’s authorized capital stock consists of 200,000,000 shares of common stock, par value $0.01 per share, and 10,000,000 shares of undesignated preferred stock. As of April 25, 2021, we had 27,966,488 shares of common stock and no shares of preferred stock issued and outstanding.

Common Stock

Voting Rights

Each outstanding share of common stock is entitled to one vote on all matters submitted to a vote of stockholders. Our certificate of incorporation does not provide for cumulative voting in connection with the election of directors, and accordingly, holders of more than 50% of the shares voting are able to elect all of the directors. The holders of a majority of the shares of common stock issued and outstanding constitute a quorum at all meetings of the stockholders for the transaction of business.

Dividend Rights

Subject to preferences that may apply to shares of preferred stock outstanding at the time, holders of outstanding shares of common stock are entitled to receive dividends out of assets legally available at the times and in the amounts as the board of directors may from time to time determine.

Liquidation Rights

Subject to applicable law and the rights, if any, of the holders of any series of preferred stock of the Company then outstanding, in the event of the liquidation, dissolution or winding-up of the Company, the holders of our common stock will be entitled to receive pro rata our assets that are legally available for distribution, after payment of all debts and other liabilities and subject to the prior rights of any holders of preferred stock then outstanding.

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Redemption, Conversion or Preemptive Rights

Holders of common stock have no redemption rights, conversion rights or preemptive rights to subscribe to any or all additional issues of shares of capital stock the Company or securities convertible into capital stock of the Company.

Listing

Currently, our common stock is listed on the Nasdaq under the ticker symbol “PBPB.”

Preferred Stock

We are authorized to issue up to 10,000,000 shares of preferred stock, par value $0.01 per share, from time to time, in one or more series. Our board of directors may, without further action by our stockholders, from time to time, direct the issuance of shares of preferred stock in series and may, at the time of issuance, determine the designations, powers, preferences, privileges, and relative participating, optional or special rights as well as the qualifications, limitations or restrictions thereof, including dividend rights, conversion rights, voting rights, terms of redemption and liquidation preferences, any or all of which may be greater than the rights of the common stock. Satisfaction of any dividend preferences of outstanding shares of preferred stock would reduce the amount of funds available for the payment of dividends on shares of our common stock. Holders of shares of preferred stock may be entitled to receive a preference payment in the event of our liquidation before any payment is made to the holders of shares of our common stock. Under specified circumstances, the issuance of shares of preferred stock may render more difficult or tend to discourage a merger, tender offer or proxy contest, the assumption of control by a holder of a large block of our securities or the removal of incumbent management. Upon the affirmative vote of a majority of the total number of directors then in office, our board of directors, without stockholder approval, may issue shares of preferred stock with voting and conversion rights that could adversely affect the holders of shares of our common stock and the market value of our common stock.

Prior to the issuance of shares of each series, the board of directors is required by the General Corporation Law of the State of Delaware (the “DGCL”), and our amended and restated certificate of incorporation to adopt resolutions and file a certificate of designation with the Secretary of State of the State of Delaware. The certificate of designation fixes for each class or series the designations, powers, preferences, rights, qualifications, limitations and restrictions, including dividend rights, conversion rights, redemption privileges and liquidation preferences.

All shares of preferred stock offered by this prospectus will, when issued, be fully paid and nonassessable and will not have any preemptive or similar rights. Our board of directors may authorize the issuance of preferred stock with voting or conversion rights that could adversely affect the voting power or other rights of the holders of the common stock. The issuance of preferred stock, while providing flexibility in connection with possible acquisitions and other corporate purposes, could, among other things, have the effect of delaying, deferring or preventing a change in our control and may adversely affect the market price of the common stock and the voting and other rights of the holders of common stock.

We will describe in a prospectus supplement relating to the class or series of preferred stock being offered the following terms:

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Unless we specify otherwise in the applicable prospectus supplement, the preferred stock will rank, relating to dividends and upon our liquidation, dissolution or winding up:

The term equity securities does not include convertible debt securities.

Exclusive Forum

The Company’s certificate of incorporation requires, to the fullest extent permitted by law, that derivative actions brought in the name of the Company, actions against directors, officers and employees for breach of fiduciary duty and other similar actions may be brought only in the Court of Chancery in the State of Delaware. Although the Company believes this provision benefits the Company by providing increased consistency in the application of Delaware law in the types of lawsuits to which it applies, the provision may have the effect of discouraging lawsuits against the Company’s directors and officers.

Indemnification of Directors and Officers

Under the DGCL, a Delaware corporation may include in its certificate of incorporation a provision that, subject to the limitations described below, eliminates or limits the personal liability of a director to the corporation or its stockholders for monetary damages for breaches of fiduciary duty as a director. Such a provision may not eliminate or limit the liability of a director for (i) any breach of the duty of loyalty to the corporation or its stockholders, (ii) acts or omissions not in good faith or that involve intentional misconduct or a knowing violation of law, (iii) the willful or negligent payment of unlawful dividends or purchases or redemptions of shares of stock, or (iv) transactions from which such director derived an improper personal benefit.

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The DGCL also provides that a Delaware corporation has the power to indemnify any person who is a party or is threatened to be made a party to any threatened, pending or completed action, suit or proceeding (whether civil, criminal, administrative or investigative) by reason of the fact that such person is or was a director, officer, employee or agent of the corporation, or is or was serving at the request of the corporation as a director, officer, employee of another entity, against reasonable expenses (including attorneys’ fees) and, in actions not brought by or in the right of the corporation, judgments, fines and amounts paid in settlement, in each case, actually and reasonably incurred in connection with such action, suit or proceeding, but only if such person acted in a manner reasonably believed to be in or not opposed to the best interests of the corporation and, with respect to any criminal action, had no reasonable cause to believe his or her conduct was unlawful, except that in any action brought by or in the right of the corporation, such indemnification may not be made if such person is adjudged liable to the corporation (unless otherwise determined by the court in which such action, suit or proceeding was brought or the Delaware Court of Chancery). In addition, under Delaware law, to the extent that a present or former director or officer of a Delaware corporation has been successful on the merits or otherwise in defense of any action, suit or proceeding referred to above or any claim, issue or matter therein, he or she must be indemnified by the corporation against expenses (including attorneys’ fees) actually and reasonably incurred by him or her. Furthermore, under Delaware law, a Delaware corporation is permitted to maintain directors’ and officers’ insurance.

Our certificate of incorporation limits the liability of our directors to the fullest extent permitted by the DGCL, and our bylaws provide that we will indemnify them to the fullest extent permitted by such law. We have entered into indemnification agreements with our directors and executive officers.

Anti-Takeover Effects of Delaware Law and the Certificate of Incorporation and Bylaws

Delaware law and the Company’s certificate of incorporation and bylaws contain provisions that may prevent or discourage a third party from acquiring the Company, even if the acquisition would be beneficial to our stockholders.

Pursuant to the certificate of incorporation, our board of directors have the authority to create one or more series of preferred stock of the Company and to fix the designations and the powers, preferences and rights, if any, and the qualifications, limitations and restrictions, if any, of shares of such new series of preferred stock of the Company and to issue shares of such series without a stockholder vote, which could be used to dilute the ownership of a hostile acquiror.

Pursuant to the certificate of incorporation, our board of directors have the power to amend the bylaws of the Company, which may allow our board of directors to take certain actions to prevent an unsolicited takeover.

The Company is also subject to Delaware law prohibiting the Company from engaging in any “business combination” with an “interested stockholder” for a period of three years subsequent to the time that the stockholder became an interested stockholder unless:

For purposes of Delaware law, an “interested stockholder” generally is defined as an entity or person (other than the corporation and any direct or indirect majority-owned subsidiary of the corporation) directly or

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indirectly beneficially owning 15% or more of the outstanding voting stock of the corporation and any entity or person affiliated or associated with such entity or person.

For purposes of Delaware law, a “business combination” includes mergers, asset sales and other transactions resulting in financial benefit to a stockholder. This Delaware law could prohibit or delay mergers or other takeover or change of control attempts with respect to the Company and, accordingly, may discourage attempts that might result in a premium over the market price for the shares held by stockholders of the Company.

Transfer Agent and Registrar

The transfer agent and registrar for the Company’s common stock is American Stock Transfer & Trust Company, LLC.

DESCRIPTION OF DEBT SECURITIES

The following description, together with the additional information we include in any applicable prospectus supplement, summarizes certain general terms and provisions of the debt securities that we may offer under this prospectus. When we offer to sell a particular series of debt securities, we will describe the specific terms of the series in a supplement to this prospectus. We will also indicate in the prospectus supplement the extent to which the general terms and provisions described in this prospectus apply to a particular series of debt securities.

We may issue debt securities either separately, or together with, or upon the conversion or exercise of or in exchange for, other securities described in this prospectus. Debt securities may be our senior, senior subordinated or subordinated obligations and, unless otherwise specified in a supplement to this prospectus, the debt securities will be our direct, unsecured obligations and may be issued in one or more series.

The debt securities will be issued under an indenture between us and a trustee to be identified in the applicable prospectus supplement. We have summarized select portions of the indenture below. The summary is not complete. The form of the indenture has been filed as an exhibit to the registration statement of which this prospectus forms a part and you should read the indenture for provisions that may be important to you. In the summary below, we have included references to the section numbers of the indenture so that you can easily locate these provisions. Capitalized terms used in the summary and not defined herein have the meanings specified in the indenture.

As used in this section only, “Potbelly,” “we,” “our” or “us” refer to Potbelly Corporation, excluding its subsidiaries, unless expressly stated or the context otherwise requires.

General

The terms of each series of debt securities will be established by or pursuant to a resolution of our board of directors and set forth or determined in the manner provided in a resolution of our board of directors, in an officer’s certificate or by a supplemental indenture. The particular terms of each series of debt securities will be described in a prospectus supplement relating to such series (including any pricing supplement or term sheet).

We can issue an unlimited amount of debt securities under the indenture that may be in one or more series with the same or various maturities, at par, at a premium, or at a discount. We will set forth in a prospectus supplement (including any pricing supplement or term sheet) relating to any series of debt securities being offered, the aggregate principal amount and the following terms of the debt securities, if applicable:

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We may issue debt securities that provide for an amount less than their stated principal amount to be due and payable upon declaration of acceleration of their maturity pursuant to the terms of the indenture. We will provide you with information on the federal income tax considerations and other special considerations applicable to any of these debt securities in the applicable prospectus supplement.

If we denominate the purchase price of any of the debt securities in a foreign currency or currencies or a foreign currency unit or units, or if the principal of and any premium and interest on any series of debt securities is payable in a foreign currency or currencies or a foreign currency unit or units, we will provide you with information on the restrictions, elections, general tax considerations, specific terms and other information with respect to that issue of debt securities and such foreign currency or currencies or foreign currency unit or units in the applicable prospectus supplement.

Transfer and Exchange

Each debt security will be represented by either one or more global securities registered in the name of The Depository Trust Company, or the Depositary, or a nominee of the Depositary (we will refer to any debt security represented by a global debt security as a “book-entry debt security”), or a certificate issued in definitive registered form (we will refer to any debt security represented by a certificated security as a “certificated debt security”) as set forth in the applicable prospectus supplement. Except as set forth under the heading “Global Debt Securities and Book-Entry System” below, book-entry debt securities will not be issuable in certificated form.

Certificated Debt Securities. You may transfer or exchange certificated debt securities at any office we maintain for this purpose in accordance with the terms of the indenture. No service charge will be made for any transfer or exchange of certificated debt securities, but we may require payment of a sum sufficient to cover any tax or other governmental charge payable in connection with a transfer or exchange.

You may effect the transfer of certificated debt securities and the right to receive the principal of, premium and interest on certificated debt securities only by surrendering the certificate representing those certificated debt securities and either reissuance by us or the trustee of the certificate to the new holder or the issuance by us or the trustee of a new certificate to the new holder.

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Global Debt Securities and Book-Entry System. Each global debt security representing book-entry debt securities will be deposited with, or on behalf of, the Depositary, and registered in the name of the Depositary or a nominee of the Depositary.

Covenants

We will set forth in the applicable prospectus supplement any restrictive covenants applicable to any issue of debt securities.

No Protection In the Event of a Change of Control

Unless we state otherwise in the applicable prospectus supplement, the debt securities will not contain any provisions which may afford holders of the debt securities protection in the event we have a change in control or in the event of a highly leveraged transaction (whether or not such transaction results in a change in control) which could adversely affect holders of debt securities.

Consolidation, Merger and Sale of Assets

We may not consolidate with or merge with or into, or convey, transfer or lease all or substantially all of our properties and assets to any person (a “successor person”) unless:

Notwithstanding the above, any of our subsidiaries may consolidate with, merge into or transfer all or part of its properties to us.

Events of Default

“Event of Default” means with respect to any series of debt securities, any of the following:

No Event of Default with respect to a particular series of debt securities (except as to certain events of bankruptcy, insolvency or reorganization) necessarily constitutes an Event of Default with respect to any other

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series of debt securities. The occurrence of certain Events of Default or an acceleration under the indenture may constitute an event of default under certain of our indebtedness or that of our subsidiaries outstanding from time to time.

If an Event of Default with respect to debt securities of any series at the time outstanding occurs and is continuing, then the trustee or the holders of not less than 25% in principal amount of the outstanding debt securities of that series may, by a notice in writing to us (and to the trustee if given by the holders), declare to be due and payable immediately the principal of (or, if the debt securities of that series are discount securities, that portion of the principal amount as may be specified in the terms of that series) and accrued and unpaid interest, if any, on all debt securities of that series. Such acceleration will not be effective until the earlier of (1) the acceleration of indebtedness under our senior secured credit facilities or (2) five business Days after receipt by us of written notice of such acceleration, at which time the principal, premium, if any, interest and any other monetary obligations on all the then outstanding series of debt securities will become due and payable immediately. In the case of an Event of Default resulting from certain events of bankruptcy, insolvency or reorganization, the principal (or such specified amount) of and accrued and unpaid interest, if any, on all outstanding debt securities will become and be immediately due and payable without any declaration or other act on the part of the trustee or any holder of outstanding debt securities. At any time after a declaration of acceleration with respect to debt securities of any series has been made, but before a judgment or decree for payment of the money due has been obtained by the trustee, the holders of a majority in principal amount of the outstanding debt securities of that series may rescind and annul the acceleration if all Events of Default, other than the non-payment of accelerated principal and interest, if any, with respect to debt securities of that series, have been cured or waived as provided in the indenture. We refer you to the prospectus supplement relating to any series of debt securities that are discount securities for the particular provisions relating to acceleration of a portion of the principal amount of such discount securities upon the occurrence of an Event of Default.

The indenture provides that the trustee will be under no obligation to exercise any of its rights or powers under the indenture unless the trustee receives indemnity satisfactory to it against any cost, liability or expense which might be incurred by it in exercising such right of power. Subject to certain rights of the trustee, the holders of a majority in principal amount of the outstanding debt securities of any series will have the right to direct the time, method and place of conducting any proceeding for any remedy available to the trustee or exercising any trust or power conferred on the trustee with respect to the debt securities of that series.

No holder of any debt security of any series will have any right to institute any proceeding, judicial or otherwise, with respect to the indenture or for the appointment of a receiver or trustee, or for any remedy under the indenture, unless:

Notwithstanding any other provision in the indenture, the holder of any debt security will have an absolute and unconditional right to receive payment of the principal of, premium and any interest on that debt security on or after the due dates expressed in that debt security and to institute suit for the enforcement of payment.

The indenture requires us, within 120 days after the end of our fiscal year, to furnish to the trustee a statement as to compliance with the indenture. If a Default or Event of Default occurs and is continuing with respect to the debt securities of any series and if it is known to a responsible officer of the trustee, the trustee

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shall mail to each holder of the debt securities of that series notice of a Default or Event of Default within 90 days after it occurs. The indenture provides that the trustee may withhold notice to the holders of debt securities of any series of any Default or Event of Default (except in payment on any debt securities of that series) with respect to debt securities of that series if the trustee determines in good faith that withholding notice is in the interest of the holders of those debt securities.

Modification and Waiver

We and the trustee may modify and amend the indenture or the debt securities of any series without the consent of any holder of any debt security:

We may also modify and amend the indenture with the consent of the holders of at least a majority in principal amount of the outstanding debt securities of each series affected by the modifications or amendments.

We may not make any modification or amendment without the consent of the holders of each affected debt security then outstanding if that amendment will:

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Except for certain specified provisions, the holders of at least a majority in principal amount of the outstanding debt securities of any series may on behalf of the holders of all debt securities of that series waive our compliance with provisions of the indenture. The holders of a majority in principal amount of the outstanding debt securities of any series may on behalf of the holders of all the debt securities of such series waive any past default under the indenture with respect to that series and its consequences, except a default in the payment of the principal of, premium or any interest on any debt security of that series; provided, however, that the holders of a majority in principal amount of the outstanding debt securities of any series may rescind an acceleration and its consequences, including any related payment default that resulted from the acceleration.

Defeasance of Debt Securities and Certain Covenants in Certain Circumstances

Legal Defeasance. The indenture provides that, unless otherwise provided by the terms of the applicable series of debt securities, we may be discharged from any and all obligations in respect of the debt securities of any series (subject to certain exceptions). We will be so discharged upon the deposit with the trustee, in trust, of money and/or U.S. government obligations or, in the case of debt securities denominated in a single currency other than U.S. Dollars, government obligations of the government that issued or caused to be issued such currency, that, through the payment of interest and principal in accordance with their terms, will provide money in an amount sufficient in the opinion of a nationally recognized firm of independent public accountants or investment bank to pay and discharge each installment of principal, premium and interest on and any mandatory sinking fund payments in respect of the debt securities of that series on the stated maturity of those payments in accordance with the terms of the indenture and those debt securities.

This discharge may occur only if, among other things, we have delivered to the trustee an opinion of counsel stating that we have received from, or there has been published by, the United States Internal Revenue Service a ruling or, since the date of execution of the indenture, there has been a change in the applicable United States federal income tax law, in either case to the effect that, and based thereon such opinion shall confirm that, the holders of the debt securities of that series will not recognize income, gain or loss for United States federal income tax purposes as a result of the deposit, defeasance and discharge and will be subject to United States federal income tax on the same amounts and in the same manner and at the same times as would have been the case if the deposit, defeasance and discharge had not occurred.

Defeasance of Certain Covenants. The indenture provides that, unless otherwise provided by the terms of the applicable series of debt securities, upon compliance with certain conditions:

The conditions include:

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Covenant Defeasance and Events of Default. In the event we exercise our option to effect covenant defeasance with respect to any series of debt securities and the debt securities of that series are declared due and payable because of the occurrence of any Event of Default, the amount of money and/or U.S. government obligations or foreign government obligations on deposit with the trustee will be sufficient to pay amounts due on the debt securities of that series at the time of their stated maturity but may not be sufficient to pay amounts due on the debt securities of that series at the time of the acceleration resulting from the Event of Default. However, we shall remain liable for those payments.

Governing Law

The indenture and the debt securities will be governed by, and construed in accordance with, the laws of the State of New York without regard to conflict of law principles that would result in the application of any law other than the law of the State of New York.

DESCRIPTION OF WARRANTS

We may issue warrants, including warrants to purchase common stock, preferred stock or debt securities or any combination of the foregoing. Warrants may be issued independently or as part of a unit with any other securities and may be attached to or separate from the underlying securities. We may issue warrants directly or under a warrant agreement to be entered into between us and a warrant agent, as detailed in the prospectus supplement relating to warrants being offered. Any warrant agent will act solely as our agent in connection with the warrants of a particular series and will not assume any obligation or relationship of agency or trust for or with any holders or beneficial owners of warrants.

A prospectus supplement relating to any warrants being offered will include specific terms relating to the offering, including a description of any other securities sold together with the warrants. These items will include:

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The descriptions of the warrants in this prospectus and in any prospectus supplement are summaries of the applicable provisions of the applicable agreements. These descriptions do not restate those agreements in their entirety and do not contain all of the information that you may find useful. We urge you to read the applicable agreements because they, and not the summaries, define your rights as holders of the warrants or any warrant units. For more information, please review the form of the relevant agreements, which will be filed with the SEC promptly after the offering of the warrants or warrant units and will be available as described under the heading “Where You Can Find More Information.”

DESCRIPTION OF UNITS

We may issue units consisting of one or more debt securities, shares of preferred stock, or shares of common stock, or any combination of such of our securities, as specified in a related prospectus supplement.

PLAN OF DISTRIBUTION

We may from time to time offer and/or sell some or all of the securities covered by this prospectus. Registration of securities covered by this prospectus does not mean, however, that those securities necessarily will be offered or sold. We may sell the securities in any of three ways (or in any combination) from time to time:

The applicable prospectus supplement will set forth the terms of the offering of such securities, including:

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We may designate agents to solicit purchases for the period of their appointment and to sell securities on a continuing basis, including pursuant to “at the market offerings.”

We may offer these securities to the public through underwriting syndicates represented by managing underwriters or through underwriters without a syndicate. If underwriters are used, the securities will be acquired by the underwriters for their own account. The underwriters may resell the securities in one or more transactions, including negotiated transactions at a fixed public offering price or at varying prices determined at the time of sale. Unless otherwise indicated in the related prospectus supplement, the obligations of the underwriters to purchase the securities will be subject to customary conditions precedent and the underwriters will be obligated to purchase all the securities offered if any of the securities are purchased. Underwriters may sell securities to or through dealers, and the dealers may receive compensation in the form of discounts, concessions or commissions from the underwriters and/or commissions from the purchasers for whom they may act as agent. Any public offering price and any discounts or concessions allowed or reallowed or paid to dealers may be changed from time to time.

Underwriters and agents may from time to time purchase and sell the securities described in this prospectus and the relevant prospectus supplement in the secondary market, but are not obligated to do so. No assurance can be given that there will be a secondary market for the securities or liquidity in the secondary market if one develops. From time to time, underwriters and agents may make a market in the securities.

In order to facilitate the offering of the securities, the underwriters may engage in transactions that stabilize, maintain or otherwise affect the price of these securities or any other securities the prices of which may be used to determine payments on these securities. Specifically, the underwriters may over-allot in connection with the offering, creating a short position in the securities for their own accounts. In addition, to cover over-allotments or to stabilize the price of the securities or of any other securities, the underwriters may bid for, and purchase, the securities or any other securities in the open market. Finally, in any offering of the securities through a syndicate of underwriters, the underwriting syndicate may reclaim selling concessions allowed to an underwriter or a dealer for distributing the securities in the offering, if the syndicate repurchases previously distributed securities in transactions to cover syndicate short positions, in stabilization transactions or otherwise. Any of these activities may stabilize or maintain the market price of the securities above independent market levels. The underwriters are not required to engage in these activities, and may end any of these activities at any time.

Underwriters named in a prospectus supplement are, and dealers and agents named in a prospectus supplement may be, deemed to be “underwriters” within the meaning of the Securities Act in connection with the securities offered thereby, and any discounts or commissions they receive from us and any profit on their resale of the securities may be deemed to be underwriting discounts and commissions under the Securities Act. We may have agreements with the underwriters, agents and dealers to indemnify them against certain civil liabilities, including liabilities under the Securities Act, or to contribute to payments they may be required to make in respect of these liabilities. Underwriters, agents and dealers may engage in transactions with or perform services for Potbelly or our subsidiaries and affiliates in the ordinary course of business.

One or more firms, referred to as “remarketing firms,” may also offer or sell the securities, if the prospectus supplement so indicates, in connection with a remarketing arrangement upon their purchase. Remarketing firms will act as principals for their own accounts or as agents for us. These remarketing firms will offer or sell the securities in accordance with a redemption or repayment pursuant to the terms of the securities. The prospectus supplement will identify any remarketing firm and the terms of its agreement, if any, with us and will describe the remarketing firm’s compensation. Remarketing firms may be deemed to be underwriters in connection with the securities they remarket. Remarketing firms may be entitled under agreements that may be entered into with

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us to indemnification by us against certain civil liabilities, including liabilities under the Securities Act and may be customers of, engage in transactions with or perform services for us in the ordinary course of business.

Unless indicated in the applicable prospectus supplement, we do not expect to apply to list the securities on a securities exchange.

LEGAL MATTERS

The validity of the securities offered by this prospectus will be passed upon for us by Greenberg Traurig, P.A., Fort Lauderdale, Florida, and counsel for any underwriters or agents, if any, will be named in the applicable prospectus supplement.

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EXPERTS

The financial statements incorporated in this prospectus by reference from the Company’s Annual Report on Form 10-K for the year ended December 27, 2020 have been audited by Deloitte & Touche LLP, an independent registered public accounting firm, as stated in their report, which is incorporated herein by reference. Such financial statements have been so incorporated in reliance upon the report of such firm given upon their authority as experts in accounting and auditing.

WHERE YOU CAN FIND MORE INFORMATION

We file annual, quarterly and current reports, proxy statements and other information with the SEC. Our SEC filings are available to the public over the Internet at the SEC’s web site at http://www.sec.gov.

The SEC allows us to incorporate by reference into this prospectus the information we file with the SEC. This means that we are disclosing important information to you by referring to other documents. The information

incorporated by reference is considered to be part of this prospectus, except for any information superseded by information contained directly in this prospectus. Information that we file later with the SEC under the Exchange Act will automatically update information in this prospectus. In all cases, you should rely on the later information over different information included in this prospectus. We incorporate by reference the documents listed below (other than any portions thereof, that, under the Exchange Act and applicable SEC rules, are not deemed “filed” under the Exchange Act) and any future filings made with the SEC under Section 13(a), 13(c), 14 or 15(d) of the Exchange Act prior to the termination of the offering of securities covered by this prospectus:

All other documents that we file with the SEC pursuant to Section 13(a), 13(c), 14 or 15(d) of the Exchange Act after the initial filing of the registration statement and prior to the termination of the offering of securities covered by this prospectus shall also be deemed to be incorporated by reference in this prospectus and to be a part hereof from the respective dates of the filing of such documents (other than any such documents, or portions thereof that, under the Exchange Act and applicable SEC rules, are not deemed “filed” under the Exchange Act). If we have incorporated by reference any statement or information in this prospectus and we subsequently modify that statement or information with information contained in this prospectus or a subsequent incorporated document, the statement or information previously incorporated in this prospectus is also modified or superseded in the same manner.

You may also request a copy of these filings, at no cost, by visiting our website at www.potbelly.com or by writing or telephoning us at:

Potbelly Corporation

111 N. Canal Street, Suite 325

Chicago, Illinois 60606

Phone: (312) 951-0600

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Exhibits to any documents incorporated by reference in this prospectus will not be sent, however, unless those exhibits have been specifically referenced in this prospectus. Information contained on our website is not incorporated by reference into this prospectus, and you should not consider information contained on our website as part of this prospectus.

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PROSPECTUS SUPPLEMENT

$40,000,000

POTBELLY CORPORATION

COMMON STOCK

WILLIAM BLAIR

Prospectus Supplement dated November 3, 2021