USS Stalwart (MSO-493) was an Agile-class minesweeper acquired by the U.S. Navy for the task of removing mines that had been placed in the water to prevent the safe passage of ships.

The second ship to be named Stalwart by the Navy, MSO-493, ex-AM-493, was laid down on 22 June 1954 by Broward Marine Shipbuilding Co. Inc., Fort Lauderdale, Florida, launched on 3 December 1955; sponsored by Mrs. Dante B. Fascelli; and commissioned on 23 April 1957.

She entered the Charleston Navy Yard for an extensive overhaul period that was completed in February 1958 which made her, at that time, the most modern minesweeper in the U.S. Atlantic Fleet.

In February 1961, Stalwart completed an overhaul and, after refresher training, participated in a joint United States-Canadian exercise off South Carolina.

She was moored to the east side of the tender pier at San Juan, Puerto Rico, on 25 June when a fire broke out in her machinery space.