Ouster, Inc.

This proxy statement is furnished in connection with the solicitation by the Board of Directors (the “Board”) of Ouster, Inc. (“Ouster,” “we,” “us,” or the “Company”) of proxies to be voted at Ouster’s Annual Meeting of Stockholders to be held on Wednesday, June 17, 2026 (the “Annual Meeting”), at 10:00 a.m., Pacific Time, and at any continuation, postponement or adjournment of the Annual Meeting. The Annual Meeting will be a completely virtual meeting, which will be conducted via live webcast. You will be able to attend the Annual Meeting and submit your questions during the Annual Meeting by visitingwww.virtualshareholdermeeting.com/OUST2026 and entering your 16-digit control number included in your Notice of Internet Availability of Proxy Materials, on your proxy card or on the instructions that accompanied your proxy materials.

Holders of record of outstanding shares of common stock at the close of business on April 24, 2026 (the “Record Date”) will be entitled to notice of and to vote at the Annual Meeting and any continuation, postponement or adjournment of the Annual Meeting. At the close of business on the Record Date, there were 63,672,949 shares of common stock issued and outstanding and entitled to vote at the Annual Meeting.

This proxy statement and the Company’s Annual Report to stockholders for the fiscal year ended December 31, 2025 (the “2025 Annual Report”) will be released on or about April 28, 2026 to Ouster’s stockholders on the Record Date.

IMPORTANT NOTICE REGARDING THE AVAILABILITY OF PROXY MATERIALS

FOR THE STOCKHOLDER MEETING TO BE HELD ON WEDNESDAY, JUNE 17, 2026

This Proxy Statement and our 2025 Annual Report to Stockholders are available at

https://materials.proxyvote.com/68989M