Company: IONQ
Filing Date: 2025-08-11
Form Type: 424B7
Source: 0001193125-25-177997
Chunk: 0

Company: IonQ, Inc.
Filing Date: 2025-08-11
Form: 424B7
Chunk 0
---
Filed Pursuant to Rule 424(b)(7)
Registration No. 333-285279

PROSPECTUS SUPPLEMENT

(To Prospectus dated
February 26, 2025)

Up to 13,220,367 Shares

Common Stock

This prospectus supplement relates to the resale by the selling stockholders referenced in this prospectus supplement (the “selling
stockholders”) of up to 13,220,367 shares of common stock, par value $0.0001 per share (the “common stock”), of IonQ, Inc. (“IonQ,” “we,” “our” and “us”). We will not receive any proceeds from
the sale of the shares of our common stock offered by this prospectus supplement.

The selling stockholders may sell the shares on any
national securities exchange on which the shares may be listed at the time of sale, on the over-the-counter market, in one or more transactions otherwise than on these
exchanges, such as privately negotiated transactions, or using a combination of these methods, and at fixed prices, at prevailing market prices at the time of the sale, at varying prices determined at the time of sale, or at negotiated prices. See
“Plan of Distribution” for more information about how the selling stockholders may sell or otherwise dispose of their shares using this prospectus supplement.

The selling stockholders may sell any, all or none of the shares offered by this prospectus supplement and we do not know if, when or in what
amounts the selling stockholders may sell their shares hereunder.

Our common stock is listed on the New York Stock Exchange (the
“NYSE”) under the symbol “IONQ.” On August 5, 2025, the last sale price of our common stock as reported on the NYSE was $42.02 per share.

Investing in our common stock involves risks. See “ Risk Factors” beginning on page S-4 of this prospectus supplement, page 4 of the accompanying prospectus and “Item 1A—Risk Factors” of our most recent report on Form 10-Kor 10-Qthat is incorporated by reference in this prospectus supplement, before making a decision to invest in our common stock.

Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of these securities or passed upon the adequacy or accuracy of this prospectus supplement. Any representation to the contrary is a criminal offense.

The date of this prospectus supplement is August 11,