Exhibit 23.1

CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

We consent to the incorporation by reference in Registration Statement No. 333-153207 on Form S-3 and Registration Statement Nos. 333-150067, 333-256955, 333-185350 and 333-218242 on Form S-8 of our reports dated February 16, 2024, relating to the financial statements of Great Lakes Dredge & Dock Corporation and the effectiveness of Great Lakes Dredge & Dock Corporation's internal control over financial reporting appearing in this Annual Report on Form 10-K for the year ended December 31, 2023.

/s/ Deloitte & Touche LLP

Chicago, Illinois

February 16, 2024