As filed with the Securities and Exchange Commission on August 29, 2019

Registration No. 333-          

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM S-8

REGISTRATION STATEMENT

UNDER

THE SECURITIES ACT OF 1933

QuinStreet, Inc.

(Exact Name of Registrant as Specified in its Charter)

950 Tower Lane, 6th Floor

Foster City, CA 94404

(650) 578-7700

(Address of Principal Executive Offices)

2010 Equity Incentive Plan

2010 Non-Employee Directors’ Stock Award Plan

(Full Titles of the Plan(s))

Douglas Valenti

Chief Executive Officer and Chairman

950 Tower Lane, 6th Floor

Foster City, CA 94404

(Name and Address of Agent for Service)

(650) 578-7700

(Telephone Number, Including Area Code, of Agent for Service)

With a copy to:

Alan F. Denenberg, Esq.

Davis Polk & Wardwell LLP

1600 El Camino Real

Menlo Park, CA 94025

(650) 752-2000

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

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 7(a)(2)(B) of the Securities Act.  ☐

CALCULATION OF REGISTRATION FEE

INCORPORATION BY REFERENCE OF CONTENTS OF REGISTRATION STATEMENT ON FORM S-8

This Registration Statement is being filed for the purpose of increasing the number of securities of the same class as other securities for which a Registration Statement of the Registrant on Form S-8 relating to the same employee benefit plans is effective. The Registrant previously registered shares of its common stock for issuance under the 2010 Equity Incentive Plan and the 2010 Non-Employee Directors’ Stock Award Plan under a Registration Statement on Form S-8 filed with the Securities and Exchange Commission on March 17, 2010 (File No.  333-165534), and registered additional shares of its common stock for issuance under such plans under Registration Statements on Form S-8 filed with the Securities and Exchange Commission on July 27, 2010 (File No. 333-168322), on August 12, 2011 (File No.  333-176272), on August 23, 2012 (File No.  333-183517), on August 20, 2013 (File No.  333-190735), on September 12, 2014 (File No.  333-198714), on August 19, 2015 (File No.  333-206472), on August 19, 2016 (File No.  333-213220), on September 8, 2017 (File No.  333-220397), and on September 12, 2018 (File No. 333-227296). Pursuant to General Instruction E to Form S-8, this Registration Statement hereby incorporates by reference the contents of the Registration Statement referenced above.

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PART II

Item 8. Exhibits

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SIGNATURES

Pursuant to the requirements of the Securities Act of 1933, as amended, the Registrant certifies that it has reasonable grounds to believe that it meets all of the requirements for filing on Form S-8 and has duly caused this Registration Statement to be signed on its behalf by the undersigned, thereunto duly authorized, in the City of Foster City, State of California, on the 29th day of August, 2019.

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POWER OF ATTORNEY

KNOW ALL PERSONS BY THESE PRESENTS, that each person whose signature appears below constitutes and appoints Douglas Valenti and Gregory Wong, and each of them, his true and lawful attorneys-in-fact and agents, with full power of substitution and re-substitution, for him in any and all capacities, to sign any and all amendments to this Registration Statement and to file the same, with all exhibits thereto and other documents in connection therewith, with the Securities and Exchange Commission, hereby ratifying and confirming that each of said attorneys-in-fact and agents, or his substitute or substitutes, may lawfully do or cause to be done by virtue hereof.

Pursuant to the requirements of the Securities Act of 1933, as amended, this Registration Statement has been signed by the following persons and in the capacities and on the dates indicated.

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Exhibit 5.1

August 29, 2019

QuinStreet, Inc.

950 Tower Lane, 6th Floor

Foster City, California 94404

Ladies and Gentlemen:

QuinStreet, Inc., a Delaware corporation (the “Company”), is filing with the Securities and Exchange Commission a Registration Statement on Form S-8 (the “Registration Statement”) for the purpose of registering under the Securities Act of 1933, as amended (the “Securities Act”), the offer and sale of an aggregate of 2,790,822 shares of the Company’s common stock, par value $0.001 per share (the “Shares”), consisting of 2,525,923 shares issuable pursuant to the 2010 Equity Incentive Plan (the “EIP”) and 264,899 shares issuable pursuant to the 2010 Non-Employee Directors’ Stock Award Plan (together with the EIP, the “Plans”), as described in the Registration Statement.

We, as your counsel, have examined originals or copies of such documents, corporate records, certificates of public officials and other instruments as we have deemed necessary or advisable for the purpose of rendering this opinion.

In rendering the opinion expressed herein, we have, without independent inquiry or investigation, assumed that (i) all documents submitted to us as originals are authentic and complete, (ii) all documents submitted to us as copies conform to authentic, complete originals, (iii) all signatures on all documents that we reviewed are genuine, (iv) all natural persons executing documents had and have the legal capacity to do so, (v) all statements in certificates of public officials and officers of the Company that we reviewed were and are accurate and (vi) all representations made by the Company as to matters of fact in the documents that we reviewed were and are accurate.

Based upon the foregoing, we advise you that, in our opinion, the Shares have been duly authorized and, when the Shares have been issued and delivered against payment therefor in accordance with the terms of the Plans, the Shares will be validly issued, fully paid and non-assessable.

We are members of the Bars of the States of New York and California and the foregoing opinion is limited to the General Corporation Law of the State of Delaware.

We hereby consent to the filing of this opinion as an exhibit to the Registration Statement. In giving this consent, we do not admit that we are in the category of persons whose consent is required under Section 7 of the Securities Act.

Very truly yours,

/s/ Davis Polk & Wardwell LLP

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Exhibit 23.1

CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

We hereby consent to the incorporation by reference in this Registration Statement on Form S-8 of our report dated August 29, 2019 relating to the financial statements, financial statement schedule and the effectiveness of internal control over financial reporting, which appears in QuinStreet, Inc.’s Annual Report on Form 10-K for the year ended June 30, 2019.

/s/ PricewaterhouseCoopers LLP

San Jose, California

August 29, 2019