As filed with the Securities and Exchange Commission on May 8, 2014.

Registration No. 333-195417

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

AMENDMENT NO. 1

TO

FORM S-1

REGISTRATION STATEMENT

UNDER

THE SECURITIES ACT OF 1933

FIREEYE, INC.

(Exact name of registrant as specified in its charter)

1440 McCarthy Blvd.

Milpitas, CA 95035

(408) 321-6300

(Address, including zip code, and telephone number, including area code, of registrant’s principal executive offices)

David G. DeWalt

Chief Executive Officer

FireEye, Inc.

1440 McCarthy Blvd.

Milpitas, CA 95035

(408) 321-6300

(Name, address, including zip code, and telephone number, including area code, of agent for service)

Copies to:

Approximate date of commencement of proposed sale to the public: From time to time after this registration statement becomes effective.

If any of the securities being registered on this Form are to be offered on a delayed or continuous basis pursuant to Rule 415 under the Securities Act, check the following box:  x

If this Form is filed to register additional securities for an offering pursuant to Rule 462(b) under the Securities Act, please check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering.  ¨

If this Form is a post-effective amendment filed pursuant to Rule 462(c) under the Securities Act, check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering.  ¨

If this Form is a post-effective amendment filed pursuant to Rule 462(d) under the Securities Act, check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering.  ¨

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, or a smaller reporting company. See the definitions of “large accelerated filer,” “accelerated filer” and “smaller reporting company” in Rule 12b-2 of the Exchange Act. (Check one):

The Registrant hereby amends this registration statement on such date or dates as may be necessary to delay its effective date until the Registrant shall file a further amendment which specifically states that this registration statement shall thereafter become effective in accordance with Section 8(a) of the Securities Act of 1933 or until the registration statement shall become effective on such date as the Securities and Exchange Commission, acting pursuant to said Section 8(a), may determine.

EXPLANATORY NOTE

This Amendment No. 1 to the Registration Statement on Form S-1 (File No. 333-195417) is solely to file Exhibits 5.1, 21.1 and 23.1. Accordingly, a preliminary prospectus has been omitted.

PART II

INFORMATION NOT REQUIRED IN PROSPECTUS

ITEM 13. OTHER EXPENSES OF ISSUANCE AND DISTRIBUTION.

The following table sets forth all the fees and expenses to be paid by the Registrant in connection with this offering. All amounts shown are estimates except for the SEC registration fee.

ITEM 14. INDEMNIFICATION OF DIRECTORS AND OFFICERS.

Section 145 of the Delaware General Corporation Law authorizes a corporation’s board of directors to grant, and authorizes a court to award, indemnity to officers, directors, and other corporate agents.

As permitted by Section 102(b)(7) of the Delaware General Corporation Law, the Registrant’s amended and restated certificate of incorporation includes provisions that eliminate the personal liability of its directors and officers for monetary damages for breach of their fiduciary duty as directors and officers.

In addition, as permitted by Section 145 of the Delaware General Corporation Law, the amended and restated certificate of incorporation and amended and restated bylaws of the Registrant provides that:

II-1

The Registrant’s policy is to enter into separate indemnification agreements with each of its directors and certain officers that provide the maximum indemnity allowed to directors and executive officers by Section 145 of the Delaware General Corporation Law and also to provide for certain additional procedural protections. The Registrant also maintains directors and officers insurance to insure such persons against certain liabilities.

These indemnification provisions and the indemnification agreements entered into between the Registrant and its directors and certain of its officers may be sufficiently broad to permit indemnification of the Registrant’s officers and directors for liabilities (including reimbursement of expenses incurred) arising under the Securities Act of 1933, as amended, or the Securities Act.

ITEM 15. RECENT SALES OF UNREGISTERED SECURITIES.

During the last three years, the Registrant has sold the following unregistered securities:

Warrants

In August 2011, the Registrant issued a warrant to purchase 60,661 shares of its Series E convertible preferred stock to one accredited investor at an exercise price of $1.36 per share.

Sales of Convertible Preferred Stock

In December 2012 and January 2013, the Registrant sold an aggregate of 4,748,591 shares of its Series F convertible preferred stock to a total of 30 accredited investors at a purchase price of approximately $10.53 per share, for an aggregate purchase price of approximately $50,000,000.

Option and Common Stock Issuances

From January 1, 2011 through September 20, 2013 (the date of the filing of the Registrant’s registration statement on Form S-8, File No. 333-191299), pursuant to the terms of its 2008 Stock Plan and its 2013 Equity Incentive Plan, the Registrant granted to its officers, directors, employees, consultants and other service providers options to purchase an aggregate of 32,184,057 shares of its common stock at exercise prices ranging from $0.57 to $20.00 per share.

From January 1, 2011 through September 20, 2013 (the date of the filing of the Registrant’s registration statement on Form S-8, File No. 333-191299), pursuant to the terms of its 2008 Stock Plan, the Registrant granted to certain officers restricted stock units covering up to an aggregate of 565,500 shares of its common stock in exchange for services.

From January 1, 2011 through September 20, 2013 (the date of the filing of the Registrant’s registration statement on Form S-8, File No. 333-191299), pursuant to the terms of its 2004 Stock Option Plan and its 2008 Stock Plan, the Registrant issued and sold to its officers, directors, employees, consultants and other service providers an aggregate of 14,477,379 shares of its common stock upon the exercise of options at exercise prices ranging from $0.05 to $7.93 per share, for an aggregate exercise price of $15,109,324.

From January 1, 2011 through September 20, 2013 (the date of the filing of the Registrant’s registration statement on Form S-8, File No. 333-191299), the Registrant issued an aggregate of 2,651,484 shares of its restricted common stock in exchange for services and sold 1,220,498 shares of its restricted common stock at a purchase price of $0.57 per share for an aggregate purchase price of $695,684.

On October 1, 2013, the Registrant issued 299,160 shares of common stock to an accredited investor upon the cashless net exercise of two outstanding warrants based on a weighted-average exercise price of approximately $0.67 per share.

II-2

On March 5, 2014, the Registrant issued 309,187 shares of common stock to an accredited investor upon the cashless net exercise of four outstanding warrants based on a weighted-average exercise price of approximately $0.72 per share.

None of the foregoing transactions involved any underwriters, underwriting discounts or commissions, or any public offering. The Registrant believes the offers, sales, and issuances of the above securities were exempt from registration under the Securities Act by virtue of (i) Section 4(a)(2) of the Securities Act (or Regulation D promulgated thereunder) as transactions not involving a public offering, (ii) Rule 701 promulgated under the Securities Act as transactions pursuant to compensatory benefit plans or contracts relating to compensation as provided under such rule, or (iii) Regulation S promulgated under the Securities Act as transactions made outside of the United States. The recipients of the securities in each of these transactions represented their intentions to acquire the securities for investment only and not with a view to or for sale in connection with any distribution thereof, and appropriate legends were placed upon the stock certificates or book-entry positions representing the shares issued in these transactions. All recipients had adequate access, through their relationships with the Registrant, to information about the Registrant. The sales of these securities were made without any general solicitation or advertising.

On September 25, 2013, in connection with the completion of the Registrant’s initial public offering, all 64,589,760 shares of its then-outstanding shares of preferred stock were automatically converted into 74,221,533 shares of common stock. The issuance of such shares was exempt from the registration requirements of the Securities Act in reliance on Section 3(a)(9) and Section 4(a)(2) of the Securities Act. The Registrant received no additional consideration for such automatic conversions.

In addition to the securities described above, the Registrant has issued securities in connection with the following acquisitions:

None of the foregoing transactions with respect to the acquisitions involved any underwriters, underwriting discounts or commissions, or any public offering. The Registrant believes that such offers, sales and issuances of the above securities in connection with the foregoing acquisitions were exempt from registration under the Securities Act by virtue of Regulation D promulgated thereunder, with respect to the transactions described in the third and fourth bullets, and Section 4(a)(2) of the Securities Act, with respect to the transactions described in the first and second bullets, as transactions by an issuer not involving a public offering. The Registrant took into account the following factors with respect to the transactions described in the first and second bullets: (i) all sales of the shares were made without any general solicitation or advertising; (ii) there were a limited number of offerees (three persons and two entities in the case of the acquisition described in the first bullet above and one offeree in the case of the acquisition described in the second bullet above); (iv) the purchasers and/or their legal representatives had access to substantial business and financial information regarding the Registrant; (v) the Registrant believes that each of the purchasers was sophisticated and capable of understanding and evaluating the risks of acquiring the Registrant’s securities; (vi) each of the purchasers made standard representations to the Registrant to ensure the availability of the Section 4(a)(2) exemption, including, without limitation, representations of their intentions to acquire the shares for investment for their own accounts and not with a view

II-3

to the resale or distribution of any shares (except, in the case of the acquisition described in the first bullet above, for a distribution by the recipient entity to its five stockholders, provided that such distribution would be exempt from the registration requirements of the Securities Act); and (vii) appropriate legends were placed upon the stock certificates issued in connection with both of these acquisitions.

ITEM 16. EXHIBITS AND FINANCIAL STATEMENT SCHEDULES.

(a) Exhibits.

We have filed the exhibits listed on the accompanying Exhibit Index of this Registration Statement.

(b) Financial Statement Schedules.

All financial statement schedules are omitted because the information called for is not required or is shown either in the consolidated financial statements or in the notes thereto.

ITEM 17. UNDERTAKINGS.

(a) The undersigned registrant hereby undertakes:

(1) To file, during any period in which offers or sales are being made, a post-effective amendment to this registration statement:

(2) That, for the purpose of determining any liability under the Securities Act of 1933, each such post-effective amendment shall be deemed to be a new registration statement relating to the securities offered therein, and the offering of such securities at that time shall be deemed to be the initial bona fide offering thereof.

(3) To remove from registration by means of a post-effective amendment any of the securities being registered which remain unsold at the termination of the offering.

(4) That, for the purpose of determining liability under the Securities Act of 1933 to any purchaser:

Each prospectus filed pursuant to Rule 424(b) as part of a registration statement relating to an offering, other than registration statements relying on Rule 430B or other than prospectuses filed in reliance on Rule 430A, shall be deemed to be part of and included in the registration statement as of the date it is first used after effectiveness. Provided, however, that no statement made in a registration statement or prospectus that is part of the registration

II-4

statement or made in a document incorporated or deemed incorporated by reference into the registration statement or prospectus that is part of the registration statement will, as to a purchaser with a time of contract of sale prior to such first use, supersede or modify any statement that was made in the registration statement or prospectus that was part of the registration statement or made in any such document immediately prior to such date of first use.

(b) Insofar as indemnification for liabilities arising under the Securities Act of 1933 may be permitted to directors, officers, and controlling persons of the Registrant pursuant to the foregoing provisions, or otherwise, the registrant has been advised that in the opinion of the Securities and Exchange Commission such indemnification is against public policy as expressed in the Act and is, therefore, unenforceable. In the event that a claim for indemnification against such liabilities (other than the payment by the registrant of expenses incurred or paid by a director, officer, or controlling person of the registrant in the successful defense of any action, suit, or proceeding) is asserted by such director, officer, or controlling person in connection with the securities being registered, the registrant will, unless in the opinion of its counsel the matter has been settled by controlling precedent, submit to a court of appropriate jurisdiction the question whether such indemnification by it is against public policy as expressed in the Act and will be governed by the final adjudication of such issue.

II-5

SIGNATURES

Pursuant to the requirements of the Securities Act of 1933, the Registrant has duly caused this registration statement to be signed on its behalf by the undersigned, thereunto duly authorized, in the City of Milpitas, State of California, on May 8, 2014.

Pursuant to the requirements of the Securities Act of 1933, this registration statement has been signed by the following persons in the capacities and on the dates indicated.

II-6

EXHIBIT INDEX

-1-

-2-

-3-