QS Quantumscape Corp

Filed Pursuant to Rule 424(b)(3)

Registration No. 333-251433

PROSPECTUS SUPPLEMENT

(To Prospectus dated May 18, 2021)

306,053,642 Shares of Class A Common Stock

6,650,000 Warrants

This Prospectus Supplement supplements the prospectus dated May 18, 2021 (as supplemented to date, the “Prospectus”), which forms a part of our Registration Statement on Post-Effective Amendment No. 3 to the Form S-1 (Registration Statement No. 333- 251433) filed with the Securities and Exchange Commission (the “Commission”) on May 17, 2021 and declared effective by the Commission on May 18, 2021.

The Prospectus and this Prospectus Supplement relate to the disposition from time to time of 1) up to 306,053,642 shares of our Class A Common Stock, which include Class A Common Stock issuable upon conversion of our Class B Common Stock, the exercise of certain private placement and public warrants (together, the “Warrants”), the exercise of certain stock options, and the vesting of certain restricted stock units, and 2) up to 6,650,000 private placement warrants, which are held or may be held by the selling securityholders named in the Prospectus. We will not receive any proceeds from the sale of our securities offered by the selling securityholders under the Prospectus. We will receive up to an aggregate of approximately $207,650,336.50 from the exercise of the Warrants assuming the exercise in full of all of the Warrants for cash at a current exercise price of $11.50 per share, less the amount that will not be received due to cashless exercises.

This Prospectus Supplement should be read in conjunction with the Prospectus, which is to be delivered with this Prospectus Supplement. This Prospectus Supplement updates, amends and supplements the information included or incorporated by reference in the Prospectus. If there is any inconsistency between the information in the Prospectus and this Prospectus Supplement, you should rely on the information in this Prospectus Supplement.

This Prospectus Supplement is not complete without, and may not be delivered or utilized except in connection with, the Prospectus, including any amendments or supplements to it.

Current Report on Form 8-K

On May 24, 2021, we filed a Current Report on Form 8-K with the Commission. The portion of the text of such Form 8-K that is treated as “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended, is attached hereto.

Investing in our securities involves a high degree of risk. In reviewing the Prospectus and this Prospectus Supplement, you should carefully consider the matters described under the heading “Risk Factors” beginning on page 6 of the Prospectus.

You should rely only on the information contained in the Prospectus, this Prospectus Supplement or any Prospectus Supplement or amendment hereto. We have not authorized anyone to provide you with different information.

Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of these securities or determined if this prospectus is truthful or complete. Any representation to the contrary is a criminal offense.

The date of this prospectus supplement is May 24, 2021.

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d)

of the Securities Exchange Act of 1934

Date of report (Date of earliest event reported): May 20, 2021

(408) 452-2000

(Registrant’s telephone number, including area code)

Not Applicable

(Former name or former address, if changed since last report)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the Registrant under any of the following provisions:

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§ 230.405) or Rule 12b-2 of the Securities Exchange Act of 1934 (§ 240.12b-2).

Emerging growth company  ☒

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 13(a) of the Exchange Act. ☐

Item 5.02. Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers.

On May 20, 2021, Celina Mikolajczak accepted an employment offer by QuantumScape Battery, Inc., a wholly-owned subsidiary of QuantumScape Corporation (the “Company”), where she will assume the title of Vice President of Manufacturing Engineering starting in July 2021. In her new role, Ms. Mikolajczak will lead the transition of the Company’s tools and manufacturing processes from research and development to production.

In connection with accepting this offer, she has resigned from the Company’s board of directors effective as of May 20, 2021.

A copy of the Company’s press release announcing Ms. Mikolajczak’s appointment is attached to this report as Exhibit 99.1 and is incorporated herein by reference.