USS Mary Louise (SP-356) was a patrol boat that served in the United States Navy from August to October 1917. Mary Louise was built as a private boat of the same name in by the Milton Point Shipyard in New York. On 24 August 1917, the U.S. Navy acquired her on a free-lease basis from her owner, J. S. Williams of Wilmington, North Carolina, for use as a patrol boat during World War I. She was placed in service as USS Mary Louise (SP-356) on 27 August 1917.
Assigned to the 6th Naval District, Mary Louise served on section patrol duties for about two months.
Mary Louise was returned to her owner on 30 October 1917.