QUINSTREET, INC

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

SCHEDULE 14A

Proxy Statement Pursuant to Section 14(a) of the

Securities Exchange Act of 1934

(Amendment No. )

Check the appropriate box:

QuinStreet, Inc.

(Name of Registrant as Specified In Its Charter)

(Name of Person(s) Filing Proxy Statement, if other than the Registrant)

Payment of Filing Fee (Check the appropriate box):

NOTICE OF ANNUAL MEETING OF STOCKHOLDERS

TO BE HELD OCTOBER 29, 2026

To our stockholders:

We will hold our annual meeting of stockholders at Metro Tower, 950 Tower Lane, Suite 1200, Foster City, California 94404 on October 29, 2026, at 3:00 P.M. local time. We are holding this meeting for the purpose of considering and voting on:

(1) Election of three Board nominees to serve as Class II directors for a three-year term expiring on the date of the 2029 annual meeting of stockholders or until their respective successors have been duly elected and qualified;

(2) Ratification of the selection of PricewaterhouseCoopers LLP as our independent registered public accounting firm for fiscal year 2027;

(3) Approval by non-binding advisory vote of the fiscal year 2026 compensation of our Named Executive Officers;

(4) Approval of an amendment to the QuinStreet, Inc. 2021 Employee Stock Purchase Plan to increase the number of shares (the “2021 ESPP Amendment”); and

(5) The transaction of any other business that properly comes before the meeting.

The stockholders of record at the close of business on August 31, 2026 will be entitled to vote at the meeting or any postponements or adjournments of the meeting.

We have elected to provide access to our proxy materials over the Internet under the SEC’s “Notice and Access” rules, which will reduce the impact of printing and mailing these materials on the environment. Stockholders will not receive printed proxy materials unless they request them or have previously elected to receive printed copies of all future proxy materials. Instead, we will mail on or about September 16, 2026 to most stockholders a Notice of Internet Availability of Proxy Materials (the “Notice”) containing instructions on how to access our proxy statement and our annual report on the Internet. Whether or not you expect to attend, we urge you to vote via the Internet in accordance with the instructions in the Notice you received in the mail and in this proxy statement. The Notice will contain instructions on how you may request printed proxy materials, including a proxy card (or voting instruction form, as applicable).

If you have received printed proxy materials, we urge you to sign, date, and promptly return the accompanying proxy card (or voting instruction form, as applicable) in the prepaid postage, pre-addressed envelope or vote via telephone or the Internet in accordance with the instructions on the proxy card (or voting instruction form, as applicable). If you attend the meeting, you may vote your shares in person as described in the proxy statement, which will revoke any prior vote.

Important Notice Regarding the Availability of Proxy Materials for the Stockholder Meeting To Be Held on October 29, 2026: This Proxy Statement and the 2026 Annual Report to Stockholders are available on the following website: https://investor.quinstreet.com/financials/annual-meeting.

By order of the Board of Directors,

/s/ Douglas Valenti

Douglas Valenti

Chief Executive Officer

September 16, 2026

Foster City, California