USS Agile (MSO-421) was an Agile-class minesweeper acquired by the U.S. Navy for the dangerous task of removing mines from minefields laid in the water to prevent ships from passing. Agile was laid down on 22 February 1954 at Stamford, Connecticut, by the Luders Marine Construction Co. as AM-421; redesignated MSO-421 on 7 February 1955; launched on 19 November 1955; sponsored by Mrs. Alice Donohue; and commissioned at the New York Naval Shipyard on 21 June 1956.