List of British parliamentarians who died in the First World War

The United Kingdom of Great Britain and Ireland declared war on the German Empire on 4 August 1914 following the invasion of Belgium by Germany, and thus participated for four years in the First World War, on the side of the Allies and against the Central Powers. Some 750,000 British men were killed in war during this conflict.

At the start of the war, the Prime Minister of the United Kingdom was the Liberal H. H. Asquith, who was reappointed following the December 1910 general election. He led a Liberal minority government, with the support without participation of Irish nationalist MPs from the Irish Parliamentary Party. Challenged for his management of the war, Herbert Asquith was forced into May 1915 to form a government of national unity including the Conservative Party and the Labour Party. The Prime Minister was forced by the Conservatives to resign in December 1916, and David Lloyd George succeeded him at the head of the coalition.

A total of 264 members of the House of Commons enlisted in the armed forces during the First World War. 23 members of the House of Commons were killed in the war (or died as a result of their participation), as were twenty members of the House of Lords and three former members of the Commons.^[1] A memorial commemorates these forty-three men, as well as the staff of the two Chambers and the soldiers who died at the front who are sons of parliamentarians, in Westminster Hall, within the grounds of the Palace of Westminster where Parliament sits.^[2]