Alan Louis Singleton was born at Sydney on 20 July 1921 to Henry Joseph and Elizabeth Jane (née Wrightson). He was working as a fireman assistant at Woy Woy on the Central Coast of New South Wales when he initially joined the Australian Military Force at nearby Gosford on 6 June 1940. He was subsequently marched to Newcastle where he officially enlisted on 19 June as a member of the 4th Infantry Battalion.

Singleton was taken on strength by the Australian Army Service Corps on 14 August 1940. He embarked from Sydney two weeks later and disembarked at Palestine on 30 September. Over the following sixteen months he transported supplies and troops throughout much of the Middle East and Greece in support of several significant operations including the Capture of Tobruk in January 1941 and the Battle of Greece in April of the same year. Following the evacuation of Greece, he was stationed at Crete for a month alongside his older brother Robert (Bob) Henry. The brothers notably formed a group of five siblings that served during the Second World War along with Paul Hedley, Sylvia Jane and Benjamin Neville.

Singleton was amongst 4,000 Allied troops evacuated from Crete on 31 May / 1 June 1940. He subsequently served in Palestine, Lebanon and Syria until February 1942. He then departed the Middle East for a period of service in Australia, disembarking in the Northern Territory on 14 April 1942. His service in the Territory included a brief detachment for special duty at Alice Springs in November 1942, and a stint with the 19th Infantry Brigade in March 1943. He was transferred to Queensland in late May of the same year until late December 1944. His last posting was in New Guinea from 3 January through to 3 September 1945 before being discharged on 6 December of the same year.

Singleton was working as a mill hand at Dulacca in the Western Downs region of Queensland in 1949, but returned to New South Wales by 1950. He married Maud (Dot) Banks around this time, and the couple settled in the Sydney suburb of Hoxton Park.

Alan Louis Singleton died at Prairiewood in Sydney on 30 September 2012.