The Entertainments National Service Association (ENSA) was an organisation established in 1939 by Basil Dean and Leslie Henson to provide entertainment for British armed forces personnel during World War II. ENSA operated as part of the Navy, Army and Air Force Institutes. It was superseded by Combined Services Entertainment (CSE) which now operates as part of the Services Sound and Vision Corporation (SSVC).

The first big wartime variety concert organised by ENSA was broadcast by the BBC to the Empire and local networks from RAF Hendon in north London on 17 October 1939. Among the entertainers appearing on the bill were Adelaide Hall, The Western Brothers and Mantovani. A newsreel of this concert showing Hall singing "We're Going to Hang out the Washing on the Siegfried Line" accompanied by Mantovani and His Orchestra exists.

Many members of ENSA later had careers in the entertainment industry after the war, including actors Terry-Thomas, Peter Sellers and Kenneth Connor.

Tap and acrobatic dancer Vivienne Hole, stage name Vivienne Fayre, a civilian aged 19, was the only ENSA member killed in the war. On 23 January 1945 in Normandy, she was being driven between shows as a passenger aboard a truck carrying stage scenery which strayed into a minefield. She was buried with full military honours in Sittard War Cemetery.