This prospectus is part of a registration statement that we filed with the Securities and Exchange Commission (the “SEC”) using the “shelf registration process.” By using a shelf registration statement, we may sell at any time, and from time to time, up to $350,000,000 of any combination of the securities described in this prospectus in one or more offerings.

This prospectus provides you with only a general description of the securities we may offer. It is not meant to be a complete description of any security. Each time we sell securities, we will provide a prospectus supplement to this prospectus that will contain specific information about the terms of that offering, including the specific amounts, prices and terms of the securities offered. We and any underwriter or agent that we may from time to time retain may also provide other information relating to an offering, including through one or more free-writing prospectuses, which we refer to as “other offering material.” The prospectus supplement as well as the other offering material may also add, update or change information contained in this prospectus or in the documents we have incorporated by reference into this prospectus. You should read this prospectus, any prospectus supplement and other offering material, together with additional information described in the section entitled “Where You Can Find More Information.” Throughout this prospectus, where we indicate that information may be supplemented in an applicable prospectus supplement or supplements, that information may also be supplemented in other offering material. If there is any inconsistency between this prospectus and the information contained in a prospectus supplement, you should rely on the information in the prospectus supplement.

Unless we state otherwise or the context otherwise requires, references to “Century Aluminum,” the “Company,” “us,” “we” or “our” in this prospectus mean Century Aluminum Company (the “Registrant”)and its consolidated subsidiaries. When we refer to “you” in this section, we mean all purchasers of the securities being offered by this prospectus and any accompanying prospectus supplement, whether they are the holders or only indirect owners of those securities.

Incorporation by Reference

The SEC allows us to “incorporate by reference” into this prospectus the information we file with it, which means that we can disclose important information to you by referring to those documents. The information that we incorporate by reference is filingconsidered to be part of this Amendment No. 1prospectus. Any statement contained or incorporated by reference in this prospectus shall be deemed to itsbe modified or superseded for purposes of this prospectus to the extent that a statement contained herein, or in any subsequently filed document which also is incorporated by reference herein, modifies or supersedes such earlier statement. Any such statement so modified or superseded shall not be deemed, except as so modified or superseded, to constitute a part of this prospectus. We incorporate by reference into this prospectus the following documents:

(a)            Annual Report on Form 10-K for the year ended December 31, 2022;

(b)           Quarterly Report on Form 10-Q for the period ended March 31, 2023;

(c)           Current Report on Form 8-K filed with the SEC on May 5, 2023; and

(d)            The description of our common stock contained in our Registration Statement on Form S-3 (File No. 333-230018)8-A filed on September 29, 2009, pursuant to Section 12(b) of the Securities Exchange Act of 1934 (the “Exchange Act”).

We also incorporate by reference any filings we make with the SEC pursuant to Sections 13(a), 13(c), 14 or 15(d) of the Exchange Act after the date of the initial registration statement of which this prospectus forms a part and prior to effectiveness of the registration statement and after the date of this prospectus and prior to the termination of any offering covered by this prospectus and any applicable prospectus supplement.

Cautionary Statement Regarding Forward-Looking Statements

Certain statements and information in this prospectus and the documents we incorporate by reference may constitute “forward-looking statements” within the meaning of Section 27A of the Securities Act and Section 21E of the Exchange Act. These forward-looking statements may be identified by the words “believe,” “expect,” “target,” “anticipate,” “intend,” “plan,” “seek,” “estimate,” “potential,” “project,” “scheduled,” “forecast” or words of similar meaning, or future or conditional verbs such as “will,” “would,” “should,” “could,” “might,” or “may.” All such forward-looking statements contained or incorporated in this prospectus which address operating performance, events or developments that we expect or anticipate may occur in the future, including, without limitation, statements related to business opportunities, awarded sales contracts, sales backlog and ongoing commercial arrangements, or statements expressing views about future operating results, are forward-looking statements. Actual results may differ materially from any or all forward-looking statements made by us. Forward-looking statements include statements about the following subjects, among other things:

Where we express an expectation or belief as to future events or results, such expectation or belief is expressed in good faith and believed to have a reasonable basis. However, our forward-looking statements are based on current expectations and assumptions that are subject to risks and uncertainties which may cause actual results to differ materially from future results expressed, projected or implied by those forward-looking statements. Important factors that could cause actual results and events to differ from those described in such forward-looking statements can be found in the risk factors and forward-looking statements cautionary language contained in Item 1A, “Risk Factors” of our Annual Report on Form 10-K, and our Quarterly Reports on Form 10-Q and in other filings made with the SEC. Although we have attempted to identify those material factors that could cause actual results or events to differ from those described in such forward-looking statements, there may be other factors that could cause results or events to differ from those anticipated, estimated or intended. Many of these factors are beyond our ability to control or predict. Given these uncertainties, the reader is cautioned not to place undue reliance on our forward-looking statements. Any forward-looking statement included in or incorporated by reference in this prospectus speaks only as of the date on which such statement is made, and other than as required under applicable securities laws, we do not assume any obligation to update, amend or clarify such statements to reflect events, new information or circumstances occurring after such date.

Century Aluminum Company

Century Aluminum Company is a global producer of primary aluminum and operates aluminum reduction facilities, or “smelters,” in the United States and Iceland. Aluminum is an internationally traded commodity, and its price is effectively determined on the London Metal Exchange (the “LME”), plus applicable regional and value-added product premiums. Our primary aluminum reduction facilities produce standard-grade and value-added primary aluminum products.

In addition to our primary aluminum assets, we own a carbon anode production facility located in the Netherlands (“Vlissingen”). Carbon anodes are consumed in the production of primary aluminum. Vlissingen supplies carbon anodes to our aluminum smelter in Grundartangi, Iceland. Each of our aluminum smelters in the United States produces anodes at on-site facilities. In May 2023, we acquired a 55% interest in Jamalco JV, which adds its bauxite mining and alumina refining operations to our existing primary aluminum production.

Our principal executive offices are located at One South Wacker Drive, Suite 1000, Chicago, IL 60606. Our telephone number is (312) 696-3101. Our website address is www.centuryaluminum.com. The information on or accessible through our website is not part of this prospectus and should not be relied upon in connection with making any investment decision with respect to the securities offered by this prospectus.

Risk Factors

Investing in our securities involves risks. You should carefully consider the risk factors described in our Annual Report on Form 10-K for the year ended December 31, 2022, our Quarterly Report on Form 10-Q for the period ended March 31, 2023 and our other reports filed from time to time with the SEC, which are incorporated by reference into this prospectus, as the same may be amended, supplemented or superseded from time to time by our filings under the Exchange Act, as well as any prospectus supplement relating to a specific security. Before making any investment decision, you should carefully consider these risks as well as other information we include or incorporate by reference in this prospectus or in any applicable prospectus supplement. For more information, see the section entitled “Where You Can Find More Information” of this prospectus. These risks could materially affect our business, results of operations or financial condition and affect the value of our securities. You could lose all or part of your investment. Additional risks and uncertainties not presently known to us or that we currently deem immaterial may also affect our business, results of operations or financial condition.

Use of Proceeds

Unless otherwise set forth in the applicable prospectus supplement, we intend to use the net proceeds of any offering of our securities for working capital and other general corporate purposes, including refinancing of debt, capital expenditures or strategic investments. Any specific allocation of the net proceeds of an offering of securities will be determined at the time of such offering and will be described in the applicable prospectus supplement or other offering material. Until we apply the net proceeds for specific purposes, we may invest net proceeds in short-term or marketable securities.

Description of Securities

This prospectus contains summary descriptions of the capital stock, debt securities and guarantees, warrants, depositary shares, subscription rights, stock purchase contracts and stock purchase units that we may offer and sell from time to time. These summary descriptions are not meant to be complete descriptions of any security. At the time of an offering and sale, this prospectus, together with the accompanying prospectus supplement, will contain the material terms of the securities being offered.

Description of Capital Stock

The following descriptions of our capital stock and of certain provisions of Delaware law do not purport to be complete and are subject to and qualified in their entirety by reference to our Amended and Restated Certificate of Incorporation (the “Certificate”), our Amended and Restated Bylaws (the “Bylaws”) and the General Corporation Law of the State of Delaware (the “DGCL”). Copies of our Certificate and Bylaws have been filed with the SEC and are filed as exhibits to the registration statement of which this prospectus forms a part.

As used in this “Description of Capital Stock,” the terms “we,” “our” and “us” refer only to Century Aluminum Company, a Delaware corporation, and not, unless otherwise indicated, to any of our subsidiaries.

As of the date hereof, our authorized capital stock consists of 200,000,000 shares, of which 195,000,000 shares are common stock, par value $0.01 per share, and 5,000,000 shares are preferred stock, par value $0.01 per share. As of February 23, 2023, there were 92,323,978 shares of common stock issued and outstanding, all of which were fully paid and non-assessable. As of December 31, 2022, there were 53,854 shares of preferred stock issued and outstanding.

Our common stock is listed on the Nasdaq Global Select Market under the symbol “CENX.”

Common Stock

Holders of our common stock are entitled to one vote for each share held on all matters submitted to a vote of stockholders, including the election of directors. The Certificate does not provide for cumulative voting in the election of directors. Accordingly, holders of a majority of the shares of our common stock entitled to vote in any election of directors may elect all the directors standing for election. Subject to any preferential rights of any outstanding series of preferred stock created by our board of directors, the holders of our common stock are entitled to receive ratably such dividends, if any, as may be declared from time to time by our board of directors from funds which are legally available for that purpose. Upon the liquidation, dissolution or winding up of Century Aluminum, the holders of our common stock are entitled to receive ratably any of our net assets available after the payment of all debts and other liabilities and subject to the prior rights of any outstanding preferred stock. Holders of our common stock have no preemptive, subscription, redemption or conversion rights. All shares of our common stock currently outstanding and those to be issued upon the completion of any offering under a prospectus supplement will be fully paid and non-assessable. The rights, preferences and privileges of holders of our common stock are subject to, and may be adversely affected by, the rights of the holders of shares of any series of our preferred stock which are currently outstanding or which we may designate and issue in the future.

Each prospectus supplement relating to a series of common stock may describe material U.S. federal income tax considerations applicable to the purchase, holding and disposition of such series of common stock.

Preferred Stock and Depositary Shares

Under the Certificate, our board of directors is authorized to issue up to 5,000,000 shares of preferred stock without any vote or action by the holders of our common stock, of which 160,000 shares are designated as Series A Convertible Preferred Stock. See “-Series A Convertible Preferred Stock.” Our board of directors may issue preferred stock in one or more series and determine for each series the dividend rights, conversion rights, voting rights, redemption rights, liquidation preferences, sinking fund terms and the number of shares constituting that series, as well as the designation thereof. Depending upon the terms of preferred stock established by our board of directors, any or all of the preferred stock could have preference over the common stock with respect to dividends and other distributions and upon the liquidation of Century Aluminum. In addition, issuance of any shares of preferred stock with voting powers may dilute the voting power of the outstanding common stock.

The particular terms of any series of preferred stock that we offer under this prospectus will be described in the applicable prospectus supplement relating to that series of preferred stock. Those terms may include:

You should refer to the certificate of designations establishing a particular series of preferred stock which will be filed with the Delaware Secretary of State and the SEC in connection with any offering of preferred stock.

Each prospectus supplement relating to a series of preferred stock may describe material U.S. federal income tax considerations applicable to the purchase, holding and disposition of such series of preferred stock.

Series A Convertible Preferred Stock

Shares Authorized and Outstanding. In 2008, we issued 160,000 shares of our Series A Convertible Preferred Stock, of which 53,854 shares were outstanding as of December 31, 2022. Glencore plc (“Glencore”) holds all shares of the issued and outstanding Series A Convertible Preferred Stock.

The issuance of common stock under our stock incentive programs, debt exchange transactions and any stock offering that excludes Glencore’s participation triggers anti-dilution provisions of the preferred stock agreement and results in the automatic conversion of shares of Series A Convertible Preferred Stock into shares of common stock. Our Series A Convertible Preferred Stock has a par value of $0.01 per share.

Dividend Rights. So long as any shares of our Series A Convertible Preferred Stock are outstanding, we may not pay or declare any dividend or make any distribution upon or in respect of our common stock or any other capital stock ranking on a parity with or junior to the Series A Convertible Preferred Stock in respect of dividends or liquidation preference, unless we, at the same time, declare and pay a dividend or distribution on the shares of Series A Convertible Preferred Stock (a) in an amount equal to the amount such holders would receive if they were the holders of the number of shares of our common stock into which their shares of Series A Convertible Preferred Stock are convertible as of the record date fixed for such dividend or distribution, or (b) in the case of a dividend or distribution on other capital stock ranking on a parity with or junior to the Series A Convertible Preferred Stock in such amount and in such form as (based on the determination of holders of a majority of the Series A Convertible Preferred Stock) will preserve, without dilution, the economic position of the Series A Convertible Preferred Stock relative to such other capital stock.

Voting Rights. The Series A Convertible Preferred Stock has no voting rights for the election of directors or on other matters where the shares of common stock have voting rights. However, we may not change the powers, preferences, or rights given to the Series A Convertible Preferred Stock, or authorize, create or issue any additional shares of Series A Convertible Preferred Stock without the affirmative vote of the holders of a majority of the shares of Series A Convertible Preferred Stock then outstanding (voting separately as a class).

Liquidation Rights. Upon any liquidation, dissolution, or winding-up of Century Aluminum, the holders of shares of Series A Convertible Preferred Stock are entitled to receive a preferential distribution of $0.01 per share out of the assets available for distribution. In addition, upon any liquidation, dissolution or winding-up of Century Aluminum, if our assets are sufficient to make any distribution to the holders of the common stock, then the holders of shares of Series A Convertible Preferred Stock are also entitled to share ratably with the holders of common stock in the distribution of Century Aluminum’s assets (as though the holders of Series A Convertible Preferred Stock were holders of that number of shares of common stock into which their shares of Series A Convertible Preferred Stock are convertible). However, the amount of any such distribution will be reduced by the amount of the preferential distribution received by the holders of the Series A Convertible Preferred Stock.

Transfer Restrictions. Glencore is prohibited from transferring shares of Series A Convertible Preferred Stock to any party other than an affiliate who agrees to become bound by certain agreements associated with these shares.

Automatic Conversion. The Series A Convertible Preferred Stock automatically converts, without any further act of Century Aluminum or any holders of Series A Convertible Preferred Stock, into shares of common stock, at a conversion ratio of 100 shares of common stock for each share of Series A Convertible Preferred Stock, upon the occurrence of any of the following automatic conversion events:

Optional Conversion. Glencore has the option to convert the Series A Convertible Preferred Stock in a tender offer or exchange offer, at the same conversion ratio as above, in which a majority of the outstanding shares of our common stock have been tendered by the holders thereof and not duly withdrawn at the expiration time of such tender or exchange offer, so long as the Series A Convertible Preferred Stock is tendered or exchanged in such offer.

Stock Combinations - Adjustments. If, at any time while the Series A Convertible Preferred Stock is outstanding, Century Aluminum combines outstanding common stock into a smaller number of shares, then the number of shares of common stock issuable on conversion of each share of Series A Convertible Preferred Stock will be decreased in proportion to such decrease in the aggregate number of shares of common stock outstanding.

Redemptions or Repurchases of Common Stock. We may not redeem or repurchase our common stock unless we redeem or repurchase, or otherwise make a payment on, a pro rata number of shares of the Series A Convertible Preferred Stock. These restrictions do not apply to our open market repurchases or our repurchases pursuant to our employee benefit plans.

Right of Redemption. The Series A Convertible Preferred Stock will be redeemed by Century Aluminum if any of the following events occur (at a redemption price based on the trading price of our common stock prior to the announcement of such event) and Glencore votes its shares of our common stock in opposition to such events:

Provisions of the Certificate of Incorporation and Bylaws that May Have an Anti-Takeover Effect

Certain provisions in the Certificate and Bylaws, as well as the DGCL, may have the effect of discouraging transactions that involve an actual or threatened change in control of Century Aluminum. In addition, provisions of the Certificate, Bylaws and the DGCL may be deemed to have an anti-takeover effect and may delay, deter or prevent a tender offer or takeover attempt that a stockholder might consider to be in its best interests.

Issuance of Preferred Stock. The Certificate provides our board of directors with the authority to issue shares of preferred stock and to set the voting rights, preferences and other terms thereof.

Business Combinations. In addition to any affirmative vote required by law, the Certificate requires either: (1) the approval of a majority of the disinterested directors, (2) the approval of the holders of at least two-thirds of the aggregate voting power of the outstanding voting shares of Century Aluminum, voting as a class, or (3) the satisfaction of certain minimum price requirements and other procedural requirements, as preconditions to certain business combinations with, in general, a person who is the beneficial owner of 10% or more of our outstanding voting stock.

Number of Directors; Removal; Vacancies. The Certificate provides that the number of directors shall not be less than three nor more than eleven. The directors shall have the exclusive power and right to set the exact number of directors within that range from time to time by resolution adopted by vote of a majority of the entire board of directors. The board can only be increased over eleven through amendment of the Certificate, which requires a resolution of the board and the affirmative vote of the holders of at least two-thirds of the aggregate voting power of the outstanding shares of stock generally entitled to vote, voting as a class.

The Certificate further provides that directors may be removed only by the affirmative vote of the holders of a majority of the outstanding shares of stock generally entitled to vote. In addition, interim vacancies or vacancies created by an increase in the number of directors may be filled only by a majority of directors then in office. The foregoing provisions would prevent stockholders from removing incumbent directors without cause and filling the resulting vacancies with their own nominees.

No Stockholder Action by Written Consent; Special Meetings. The Certificate generally provides that stockholder action may be taken only at an annual or special meeting of stockholders and cannot be taken by written consent in lieu of a meeting. The Certificate and Bylaws also provide that, subject to the rights of the holders of any class or series of our preferred stock, special meetings of the stockholders may only be called by the board of directors, the executive committee or by the secretary of the Company upon written request of stockholders who have owned, in the aggregate, not less than 10% of all outstanding shares of common stock continuously for at least one year preceding such written request.

Stockholder Proposals. The Bylaws establish an advance notice procedure for nominations (other than by or at the direction of our board of directors) of candidates for election as directors at, and for proposals to be brought before, an annual meeting of stockholders. Subject to any other applicable requirements, the only business that may be conducted at an annual meeting is that which has been brought before the meeting by, or at the direction of, the board or by a stockholder who has given to the secretary of Century Aluminum timely written notice, in proper form, of the stockholder’s intention to bring that business before the meeting. In addition, only persons who are nominated by, or at the direction of, the board, or who are nominated by a stockholder who has given timely written notice, in proper form, to the secretary prior to a meeting at which directors are to be elected, will be eligible for election as directors.

Amendment of Certain Certificate Provisions or Bylaws. The Certificate requires the affirmative vote of the holders of at least two-thirds of the aggregate voting power of the outstanding shares of our stock generally entitled to vote, voting as a class, to amend certain provisions of the Certificate and Bylaws.

Section 203 of the DGCL. We are subject to Section 203 of the DGCL, which generally prohibits a publicly-held Delaware corporation from engaging in a “business combination” with an “interested stockholder” for a period of three years after the date of the transaction in which the person became an interested stockholder, unless: (1) prior to such date the board of directors of the corporation approved either the business combination or the transaction in which the person became an interested stockholder, (2) upon consummation of the transaction that resulted in the stockholder becoming an interested stockholder, the interested stockholder owned at least 85% of the outstanding stock of the corporation, excluding shares owned by directors who are also officers of the corporation and shares owned by certain employee stock plans, or (3) on or after such date the business combination is approved by the board of directors of the corporation and by the affirmative vote of at least two-thirds of the outstanding voting stock of the corporation that is not owned by the interested stockholder. A “business combination” generally includes mergers, asset sales and similar transactions between the corporation and the interested stockholder, and other transactions resulting in a financial benefit to the interested stockholder. An “interested stockholder” is a person who, together with affiliates and associates, owns 15% or more of the corporation’s voting stock or who is an affiliate or associate of the corporation and, together with his affiliates and associates, has owned 15% or more of the corporation’s voting stock within three years.

Limitation of Liability of Directors

The Certificate contains a provision eliminating the personal liability of our directors to us and our stockholders to the fullest extent permitted by applicable law. The Certificate also contains provisions generally providing for indemnification and advancement of expenses to our directors and officers to the fullest extent permitted by applicable law. In addition, we have entered into indemnification agreements with our directors.

Transfer Agent and Registrar

Computershare Trust Company, N.A. acts as transfer agent and registrar for our common stock.

Description of Debt Securities and Guarantees

The following description, together with the additional information that may be included in any applicable prospectus supplement and in any related free-writing prospectuses, summarizes the material terms and provisions of the debt securities that the Company may offer under this prospectus. While the terms summarized below will apply generally to any debt securities that the Company may offer, the particular terms of any debt securities will be described in more detail in the applicable prospectus supplement. The terms of any debt securities offered under a prospectus supplement may differ from the terms described below.

The Company may issue debentures, notes, bonds or other evidences of indebtedness, which we refer to as debt securities, from time to time in one or more distinct series. The debt securities may be senior debt securities or subordinated debt securities. If the Company issues debt securities pursuant to an indenture, the trustee under such indenture will be specified in the applicable prospectus supplement. The specific terms of debt securities being offered will be described in the applicable prospectus supplement. The statements and descriptions in this prospectus or in any prospectus supplement or any document incorporated by reference in this prospectus or applicable prospectus supplement regarding provisions of debt securities and any indentures are summaries of those provisions, do not purport to be complete and are subject to, and are qualified in their entirety by reference to, all of the provisions of the debt securities and the indentures (including any amendments or supplements the Company may enter into from time to time which are permitted under the debt securities or any indenture) to be entered into between the Company and the trustee named in the applicable prospectus supplement, which will be filed by amendment as an exhibit-only filingexhibit to the registration statement of which this prospectus is a part or as an exhibit to a periodic report filed under the Exchange Act, including the definitions of specified terms used in the indenture, and the Trust Indenture Act of 1939, as amended (the “Trust Indenture Act”). You should read the summary below, the applicable prospectus supplement and the indenture and any related documents before making your investment decision.

The applicable prospectus supplement will set forth the terms of the debt securities or any series thereof, including, if applicable:

This prospectus is part of a registration statement that provides that the Company may issue debt securities from time to time in one or more series under one or more indentures, in each case with the same or various maturities, at par or at a discount. Unless otherwise indicated in the applicable prospectus supplement, the aggregate principal amount of debt securities that may be issued under the applicable indenture is unlimited. Unless otherwise indicated in the applicable prospectus supplement, the Company may issue additional debt securities of a particular series without the consent of the holders of the debt securities of such series outstanding at the time of the issuance.

We intend to disclose any restrictive covenants for any issuance or series of debt securities in the applicable prospectus supplement. Unless otherwise indicated in the applicable prospectus supplement, the debt securities will not be listed on any securities exchange.

Each prospectus supplement will describe any guarantees of debt securities for the sole purpose of filing an updated auditor consent as Exhibit 23.1. This Amendment No. 1 does not modify any provisionbenefit of the series of debt securities to which it relates. Debt securities issued by Century Aluminum may be guaranteed by any of the subsidiary registrants under the registration statement of which this prospectus forms a part. The guarantees will be full and unconditional on a joint and several basis.

Description of Warrants

The following is a general description of the terms of the warrants we may issue from time to time. This description is subject to the detailed provisions of a warrant agreement to be entered into between us and a warrant agent we select at the time of issue and the description in the prospectus supplement relating to the applicable series of warrants.

General

We may issue warrants to purchase debt securities, preferred stock, common stock or any combination thereof. Such warrants may be issued independently or together with any such securities and may be attached to or separate from such securities. We may issue each series of warrants under a separate warrant agreement to be entered into between a warrant agent and us. The warrant agent will act solely as our agent and will not assume any obligation or relationship of agency for or with holders or beneficial owners of warrants.

A prospectus supplement will describe the particular terms of any series of warrants we may issue, including the following:

Amendments and Supplements to Warrant Agreement

We and the warrant agent may amend or supplement the warrant agreement for a series of warrants without the consent of the holders of the warrants issued thereunder to effect changes that are not inconsistent with the provisions of the warrants and that do not materially and adversely affect the interests of the holders of the warrants.

Description of Subscription Rights

We may issue subscription rights to purchase debt securities, preferred stock, common stock or other securities. These subscription rights may be issued independently or together with any other security offered hereby and may or may not be transferable by the purchaser receiving the subscription rights in such offering. In connection with any offering of subscription rights, we may enter into a standby arrangement with one or more underwriters or other purchasers pursuant to which the underwriters or other purchasers may be required to purchase any securities remaining unsubscribed after such offering.

The applicable prospectus supplement will describe the specific terms of any offering of subscription rights for which this prospectus is being delivered. Each applicable prospectus supplement may also describe material U.S. federal income tax considerations applicable to the purchase, holding and disposition of such subscription rights. A holder or prospective holder of subscription rights should refer to the applicable prospectus supplement for more specific information.

Description of Stock Purchase Contracts and Stock Purchase Units

We may issue stock purchase contracts, representing contracts obligating holders to purchase from us, and requiring us to sell to the holders, a specified number of shares of common stock at a future date or dates.

The price per share of common stock may be fixed at the time the stock purchase contracts are issued or may be determined by reference to a specific formula set forth in the stock purchase contracts. The stock purchase contracts may be issued separately or as a part of units, or stock purchase units, consisting of a stock purchase contract and either (x) senior debt securities, senior subordinated debt securities, subordinated debt securities or junior subordinated debt securities, or (y) debt obligations of third parties, including U.S. Treasury securities, in each case, securing the holder’s obligations to purchase our common stock under the stock purchase contracts. The stock purchase contracts may require us to make periodic payments to the holders of the stock purchase contracts or vice versa, and such payments may be unsecured or prefunded on some basis. The stock purchase contracts may require holders to secure their obligations thereunder in a specified manner and in certain circumstances we may deliver newly issued prepaid stock purchase contracts, or prepaid securities, upon release to a holder of any collateral securing such holder’s obligations under the original stock purchase contract. The applicable prospectus supplement will describe the terms of any stock purchase contracts or stock purchase units and, if applicable, prepaid securities. Each applicable prospectus supplement may also describe material U.S. federal income tax considerations applicable to the purchase, holding and disposition of any stock purchase contracts or stock purchase units and, if applicable, prepaid securities.

Plan of Distribution

The Company may sell common stock, preferred stock, debt securities, warrants, depositary shares, subscription rights, stock purchase contracts and/or stock purchase units in one or more of the following ways from time to time:

Any public offering prices, discounts or concessions allowed or reallowed or paid to dealers may be changed from time to time.

If underwriters are used in the sale, the underwriters will acquire the offered securities for their own account and may resell them from time to time in one or more transactions, including negotiated transactions, at a fixed public offering price or at varying prices determined at the time of sale. The offered securities may be offered either to the public through underwriting syndicates represented by one or more managing underwriters or by one or more underwriters without a syndicate. Unless otherwise set forth in a prospectus supplement, the obligations of the underwriters to purchase any series of securities will be subject to certain conditions precedent and the underwriters will be obligated to purchase all of such series of securities if any are purchased.

In connection with underwritten offerings of the offered securities and in accordance with applicable law and industry practice, underwriters may over-allot or effect transactions that stabilize, maintain or otherwise affect the market price of the offered securities at levels above those that might otherwise prevail in the open market, including by entering stabilizing bids, effecting syndicate covering transactions or imposing penalty bids, each of which is described below:

In compliance with the guidelines of the Financial Industry Regulatory Authority, or FINRA, the aggregate maximum discount, commission, agency fees, or other items constituting underwriting compensation to be received by any FINRA member or independent broker-dealer will not exceed 8% of any offering pursuant to this prospectus and any applicable prospectus supplement; however, we anticipate that the maximum commission or discount to be received in any particular offering of securities will be less than this amount.

No FINRA member may participate in any offering of securities made under this prospectus if such member has a conflict of interest under FINRA Rule 5121, including if 5% or more of the net proceeds, not including underwriting compensation, of any offering of securities made under this prospectus will be received by a FINRA member participating in the offering or affiliates or associated persons of such FINRA members, unless a qualified independent underwriter has participated in the offering or the offering otherwise complies with FINRA Rule 5121.

These transactions may be effected on the Nasdaq Global Select Market, in the over-the-counter market, or otherwise. Underwriters are not required to engage in any of these activities, or to continue such activities if commenced.

If a dealer is used in the sale, we will sell such offered securities to the dealer, as principal. The dealer may then resell the offered securities to the public at varying prices to be determined by that dealer at the time for resale. The names of the dealers and the terms of the transaction will be set forth in the prospectus supplement relating to that transaction.

Offered securities may be sold directly by us to one or more institutional purchasers, or through agents designated by us from time to time, at a fixed price or prices, which may be changed, or at varying prices determined at the time of sale. Any agent involved in the offer or sale of the offered securities in respect of which this prospectus is delivered will be named, and any commissions payable by us to such agent will be set forth in the prospectus supplement relating to that offering, unless otherwise indicated in such prospectus supplement, any such agent will be acting on a best efforts basis for the period of its appointment.

Underwriters, dealers and agents may be entitled under agreements entered into with us to indemnification by us against certain civil liabilities, including liabilities under the Securities Act, or to contribution with respect to payments that the underwriters, dealers or agents may be required to make in respect thereof. Underwriters, dealers and agents may be customers of, engage in transactions with, or perform services for us and our affiliates in the ordinary course of business.

Under the securities laws of some states, the securities offered by this prospectus may be sold in those states only through registered or licensed brokers or dealers.

Any person participating in the distribution of common stock registered under the registration statement that includes this prospectus will be subject to applicable provisions of the Exchange Act, and applicable SEC rules and regulations, including, among others, Regulation M, which may limit the timing of purchases and sales of any of our common stock by any such person. Furthermore, Regulation M may restrict the ability of any person engaged in the distribution of our common stock to engage in market-making activities with respect to our common stock. These restrictions may affect the marketability of our common stock and the ability of any person or entity to engage in market-making activities with respect to our common stock.

Other than our common stock, which is listed on the Nasdaq Global Select Market, each of the securities issued hereunder will be a new issue of securities, will have no prior trading market, and may or may not be listed on a national securities exchange. Any common stock sold pursuant to a prospectus supplement will be listed on the Nasdaq Global Select Market, subject to official notice of issuance. Any underwriters to whom we sell securities for public offering and sale may make a market in the securities, but such underwriters will not be obligated to do so and may discontinue any market making at any time without notice. We cannot assure you that there will be a market for the offered securities.

Validity of the Securities

The validity of the securities being offered hereby will be passed upon for us by Vedder Price P.C., Chicago, Illinois, and for any underwriters or agents by counsel named in the applicable prospectus supplement.

Experts

The financial statements of Century Aluminum Company and subsidiaries incorporated by reference in this prospectus, and the effectiveness of Century Aluminum Company and subsidiaries’ internal control over financial reporting have been audited by Deloitte & Touche LLP, an independent registered public accounting firm, as stated in their reports. Such financial statements are incorporated by reference in reliance upon the reports of such firm, given their authority as experts in accounting and auditing.

Where You Can Find More Information

We have filed with the SEC a registration statement under the Securities Act of 1933 to which this prospectus relates. This prospectus, which forms a part of the Registration Statement. Accordingly,registration statement, does not contain all the information included in the registration statement and in the exhibits attached or incorporated by reference in the registration statement. For further information about us and our securities, you should refer to the registration statement and to any applicable supplement(s) to this Amendment No. 1 consists of onlyprospectus.

We file annual, quarterly, current reports, proxy statements and other information with the facing page, this Explanatory NoteSEC. Our SEC filings, including the registration statement and Part IIthe exhibits and schedules thereto are also available to the public from the SEC’s website at www.sec.gov. You can also access our SEC filings through our website at www.centuryaluminum.com. Except as expressly set forth below, we are not incorporating by reference the contents of the Registration Statement.SEC website or our website into this prospectus.

Information that we file later with the SEC will automatically update and supersede this information. This means that you must look at all of the SEC filings that we incorporate by reference to determine if any of the statements in this prospectus or in any documents previously incorporated by reference have been modified or superseded. See “Incorporation by Reference.”

You may request a copy of these filings and any exhibit incorporated by reference in these filings at no cost, by writing or telephoning us at the following address or number:

Century Aluminum Company
One South Wacker Drive, Suite 1000
Chicago, Illinois 60606
(312) 696-3101
Attn: Secretary