ONTO INNOVATION INC.

Rule 10b5-1 Plan Elections

During the fiscal quarter ended June 30, 2026, the following officers and directors (as defined in Rule 16a-1(f) under the Exchange Act) adopted or terminated a “Rule 10b5-1 trading arrangement” or “non-Rule 10b5-1 trading arrangement” (as those terms are defined in Item 408 of Regulation S-K), as follows:

On April 29, 2026, Michael P. Plisinski, the Company's Chief Executive Officer, terminated a previously adopted trading plan intended to satisfy the affirmative defense conditions of Rule 10b5‑1(c) (a “10b5‑1 Plan”). Mr. Plisinski’s 10b5‑1 Plan had been adopted on March 9, 2026 (the “March Plisinski Plan”) and provided for the potential sale of up to 65,937 shares of Common Stock, subject to specified price, volume and timing conditions. No transactions were effected under the March Plisinski Plan during the quarter ended June 30, 2026 prior to its termination. The termination of the March Plisinski Plan was made in accordance with its terms and applicable law. Following such termination, on May 28, 2026, Mr. Plisinski adopted a new Rule 10b5-1 Plan providing for the sale from time to time of an aggregate of up to 50,000 shares of Common Stock (the “May Plisinski Plan”). The duration of the May Plisinski Plan is until February 15, 2027, or earlier if all transactions under the May Plisinski Plan are completed.

On May 5, 2026, Yoon Ah E. Oh, the Company's Senior Vice President & General Counsel and Corporate Secretary, terminated a previously adopted 10b5-1 Plan (the “Oh 10b5‑1 Plan”). The Oh 10b5‑1 Plan had been adopted on February 24, 2026 and provided for the potential sale of up to 10,278 shares of Common Stock, subject to specified price, volume and timing conditions. No transactions were effected under the Oh 10b5‑1 Plan during the quarter ended June 30, 2026 prior to its termination. The termination of the Oh 10b5‑1 Plan was made in accordance with its terms and applicable law. Following such termination, Ms. Oh did not enter into a new Rule 10b5‑1 trading arrangement during the quarter.

On May 22, 2026, Susan D. Lynch, amember of the Board, adopted a 10b5-1 Plan providing for the sale from time to time of an aggregate of up to 1,000 shares of Common Stock (the “Lynch 10b5-1 Plan”). The Lynch 10b5-1 Plan is intended to satisfy the affirmative defense in Rule 10b5-1(c). The duration of the Lynch 10b5-1 Plan is until May 21, 2027, or earlier if all transactions under the Lynch 10b5-1 Plan are completed.

On June 11, 2026, David B. Miller, amember of the Board, adopteda 10b5-1 Plan providing for the sale from time to time ofan aggregate of up to 2,000 shares of Common Stock (the “Miller 10b5-1 Plan”). The Miller 10b5-1 Plan is intended to satisfy the affirmative defense in Rule 10b5-1(c). The duration of the Miller 10b5-1 Plan is until June 11, 2027, or earlier if all transactions under the Miller 10b5-1 Plan are completed.