USS Owasco was a Unadilla-class gunboat built for the Union Navy during the American Civil War. She was named for Owasco Lake. Owasco, built by , was launched at Mystic, Connecticut, 5 October 1861; delivered to the Navy at New York Navy Yard 6 December 1861; and commissioned there 23 January 1862, Lt. John Guest in command. Owasco participated in the bombardment and capture of Galveston, Texas 3 October; but, on New Year’s day, was driven out of that port by Confederates in cotton clad steamers.