Private Leslie Joseph Allen enlisted to the Second Australian Imperial Force on 16 April 1941. He completed his training in Tamworth, New South Wales, and went on to serve with 2/19 Australian Infantry Battalion and 2/18 Australian Infantry Battalion in Malaya. In February 1942, Private Allen was declared missing, after Singapore fell to the Japanese. He was later presumed to have died on 15 February 1942. Private Allen is commemorated at Singapore Memorial.