Exhibit 23.1

CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

We have issued our reports dated March 16, 2018 with respect to the consolidated financial statements, and internal control over financial reporting of Delcath Systems, Inc. contained in the Registration Statement. We consent to the use of the aforementioned reports in the Registration Statement, and to the use of our name as it appears under the caption “Experts”.

/s/ Grant Thornton, LLP

New York, New York

April 9, 2018