Exhibit 32.1

CERTIFICATION PURSUANT TO
18 U.S.C. SECTION 1350,
AS ADOPTED PURSUANT TO
SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

In connection with the Annual Report on Form 10-K of Supernova Partners Acquisition Company III, Ltd. (the “Company”) for the year ended December 31, 2021, as filed with the Securities and Exchange Commission (the “Report”), I, Robert D. Reid, Chief Executive Officer of the Company, certify, pursuant to 18 U.S.C. §1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002, that:

1.The Report fully complies with the requirements of Section 13(a) or 15(d) of the Securities Exchange Act of 1934, as amended; and

2.To my knowledge, the information contained in the Report fairly presents, in all material respects, the financial condition and results of operations of the Company as of and for the period covered by the Report.

March 25, 2022

By:

/s/ Robert D. Reid

 

Name:

Robert D. Reid

 

Title:

Chief Executive Officer and Director (Principal Executive Officer)