The 55th Battalion, CEF was an infantry battalion of the Canadian Expeditionary Force during the Great War. The 55th Battalion was authorized on 7 November 1914 and embarked for Britain on 30 October 1915. It provided reinforcements for the Canadian Corps in the field until 6 July 1916, when its personnel were absorbed by the 40th Battalion, CEF. The battalion was disbanded on 21 May 1917.