Exhibit 16.1

April 5, 2017                                     

U.S. Securities and Exchange Commission

Office of the Chief Accountant

100 F Street, N.E.

Washington, DC 20549

Re: Orion Group Holdings, Inc. (File No. 001-33891)

Ladies and Gentlemen:

We have read Item 4.01 of Form 8-K dated April 5, 2017, of Orion Group Holdings, Inc. and are in agreement with the statements contained in the 2^nd and 3^rd paragraphs on page 3 therein. We have no basis to agree or disagree with other statements of the registrant contained therein.

/s/ Ernst & Young LLP