Chester T. O'Brien sailed from New York 10 November for convoy escort duty between Leyte and Manus, to Palau, and throughout the Philippines until 20 April 1945.

From 11 August 1945 Chester T. O'Brien had convoy escort duty in the Philippines and participated in redeployment of forces in the Far East until 25 November, when she sailed with homeward bound troops for San Pedro, California, arriving 17 December 1945.

Chester T. O'Brien was recommissioned 28 March 1951, departed San Diego 22 June for Newport, Rhode Island, and arrived at her new homeport 11 July.

Participation in Operation Springboard (5–30 January 1953) preceded another assignment with the Fleet Sonar School (30 March – 23 June), and on 8 July Chester T. O'Brien departed Newport for a midshipman cruise to ports of northern Europe (Bergen, Norway and Copenhagen, Denmark) and Guantanamo Bay, Cuba, returning to Narragansett Bay 5 September.

Overhaul, training, and antisubmarine exercises were her employment until 19 July 1954, when she sailed again on a midshipmen cruise to Quebec and Cuba, returning 21 August.