Cockrill cleared Norfolk, Virginia, on 23 February 1944 on convoy escort duty bound for Casablanca, French Morocco, returning to the United States at New York City on 5 April 1944.

After training and repairs, she conducted various operations off the United States East Coast until 24 July 1944, when she cleared Norfolk for a convoy to Bizerte, French Tunisia, returning to New York on 7 September 1944.

Taking station in a barrier of carrier groups in position from Greenland to the Carolinas against a large number of German submarines (U-boats), Cockrill participated on 24 April 1945 in an attack on U-546, which was forced to the surface and was scuttled by its crew.

Cockrill sailed from New York 19 May for Charleston, South Carolina; Guantánamo Bay, Cuba; the Panama Canal, and San Diego, California where she arrived on 14 July 1945.

Assigned to convoy escort duty, she operated from Saipan and Guam to Okinawa and Japanese ports in support of the occupation of Japan.