USS St. Mary's or USS St. Marys has been the name of more than one United States Navy ship, and may refer to:USS St. Mary's (1798), a galley built in 1798 and transferred to the United States Revenue Cutter Service in 1801 USS St. Mary's (1844), a sloop-of-war in commission from 1844 to 1873 St. Mary's (SP-1457), a patrol boat in service from 1917 to 1918 USS St. Mary's (APA-126), an attack transport in commission from 1944 to 1946