USS Leader (PYc-42) was a patrol boat acquired by the U.S. Navy for the task of patrolling coastal areas during World War II when there was the danger of enemy submarine activity. The first ship to be named Leader by the Navy, PYc-42, ex-Curlew, was built by White & Co. Ltd., Southampton, England, in 1927; acquired by the Navy from F. S. Molson, Montreal, Canada, 24 October 1942; and commissioned the same day.