USS Seagull (MCS(O)-55/AMS-55/YMS-402) was a YMS-1-class minesweeper of the YMS-135 subclass built for the United States Navy during World War II.

Seagull was laid down as YMS-402 on 24 July 1942 by Henry B. Nevins, Inc., City Island, Bronx; launched on 17 April 1943; and commissioned on 26 June 1943.

After the cessation of hostilities in the Pacific, she prepared for postwar minesweeping activities; and, at the end of August 1945, she sailed for Okinawa and Japan.

Placed in service again, YMS-402 departed New York on 30 October and moved north to the St. Lawrence, whence she proceeded to Buffalo, where she served as a naval reserve training ship until after the outbreak of war in Korea.

Then, in 1955, Seagull, redesignated MSC(O)-55 on 7 February, was transferred to Charleston, South Carolina, whence, for the remainder of her career, she conducted operations which took her along the southeastern Atlantic seaboard, along the ‘gulf coast, and into the Caribbean as a unit of MinRon 4.