Exhibit 13.1

Certification by the Principal Executive Officer and Principal Financial Officer 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 20-F of Oculis Holding AG (the “Company”) for the fiscal year ended December 31, 2023, as filed with the Securities and Exchange Commission on the date hereof (the “Report”), I, Riad Sherif, Chief Executive Officer of the Company and Sylvia Cheung, Chief Financial Officer of the Company, pursuant to 18 U.S.C. § 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002, each hereby certifies that, to the best of his knowledge:

(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) The information contained in the Report fairly presents, in all material respects, the financial condition and results of operations of the Company.

Date: March 19, 2024

/s/ Riad Sherif

Chief Executive Officer

(Principal Executive Officer)

/s/ Sylvia Cheung

Chief Financial Officer

(Principal Financial Officer)

This certification accompanies the Form 20-F to which it relates, is not deemed filed with the Securities and Exchange Commission and is not to be incorporated by reference into any filing of the Company under the Securities Act of 1933, as amended, or the Securities Exchange Act of 1934, as amended (whether made before or after the date of the Form 20-F), irrespective of any general incorporation language contained in such filing.