Exhibit 13.1

CERTIFICATION OF MIKKEL GLEERUP, CHIEF EXECUTIVE OFFICER OF CADELER A/S, AND PETER BROGAARD HANSEN, CHIEF FINANCIAL OFFICER OF CADELER A/S, PURSUANT TO SECTION 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 of Cadeler A/S (the "Company") on Form 20-F for the period ending December 31, 2025, as filed with the Securities and Exchange Commission on the date hereof (the "Report"), the undersigned hereby certify that to the best of our knowledge:

1.    The Report fully complies with the requirements of Section 13(a) or 15(d) of the Securities Exchange Act of 1934; 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 24, 2026

By:

/s/ Mikkel Gleerup

By:

/s/ Peter Brogaard Hansen

Name:    Mikkel Gleerup

Name:    Peter Brogaard Hansen

Title: Chief Executive Officer

Title: Chief Financial Officer