The Captain class was the designation given to 78 frigates of the Royal Navy, constructed in the United States, launched in 1942–1943 and delivered to the United Kingdom under the provisions of the Lend-Lease agreement (under which the United States of America supplied the United Kingdom and other Allied nations with materiel between 1941 and 1945). They were drawn from two classes of the American destroyer escort (originally "British Destroyer Escort") classification: 32 of the GMT (Evarts) Type and 46 of the TE (Buckley) Type. Upon reaching the UK the ships were substantially modified by the Royal Navy, making them distinct from the US Navy destroyer escort ships.

Captain-class frigates acted in the roles of convoy escorts, anti-submarine warfare vessels, coastal forces control frigates and headquarters ships for the Normandy landings. During the course of World War II this class participated in the sinking of at least 34 German submarines and a number of other hostile craft; 15 of the 78 Captain-class frigates were either sunk or written off as a constructive total loss.

In the post-war period, all of the surviving Captain-class frigates except one (HMS Hotham) were returned to the US Navy before the end of 1947 in order to reduce the amount payable under the provisions of the Lend-Lease agreement; the last Captain-class frigate was returned to United States custody in March 1956.