USS Chester T. O’Brien (DE-421) was a John C. Butler-class destroyer escort acquired by the U.S. Navy during World War II. The primary purpose of the destroyer escort was to escort and protect ships in convoy, in addition to other tasks as assigned, such as patrol or radar picket. Chester T. O'Brien (DE-421) was named in honor of Platoon Sergeant Chester Thomas O'Brien who was awarded the Silver Star medal for heroic service at Guadalcanal.