Exhibit 23.1

CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

We hereby consent to the incorporation by reference in the Registration Statement on Form S-3 (No. 333-152078) of OneBeacon U.S. Holdings, Inc. of our report dated March 16, 2011 relating to the financial statements and financial statement schedules which appears in this Form 10-K.

/s/ PricewaterhouseCoopers LLP

PricewaterhouseCoopers LLP

New York, New York

March 16, 2011