The 1939–1945 Star is a military campaign medal instituted by the United Kingdom on 8 July 1943 for award to British and Commonwealth forces for service in the Second World War.

Two clasps were instituted to be worn on the medal ribbon, Battle of Britain and Bomber Command.

Some ribbon issues to overseas troops were delayed, but many had been received by the end of 1943 and were worn by recipients throughout the remainder of the war.

[4][16] By March 1944 1,600,000 personnel had received 1939-1943 Star ribbon bars, with further awards made by the end of the war.

Two clasps were instituted to be worn on the medal ribbon, along with rosettes to be worn on the ribbon bar of the medal to denote the award of a clasp:[1][2][18] The 1939–1945 Star was awarded for specified periods of operational service overseas between 3 September 1939 and either 8 May 1945 in Europe or 2 September 1945 in the Far East theatre.

The recipient's name was impressed on the reverse of the stars awarded to Indians, South Africans and, after a campaign led by veteran organisations, to Australians.

[26] In the case of South Africans and Australians, this consisted of the recipient's force number, initials and surname in block capitals, with awards to Indians also showing the service arm or corps.

They are inscribed "BATTLE OF BRITAIN" and "BOMBER COMMAND" respectively and were designed to be sewn onto the medal's ribbon.

On 6 April 1952 the Union of South Africa instituted its own range of military decorations and medals.