Bruce Warren Fleming was born on 16 February 1915 at Woollahra, Sydney, New South Wales to Alexander George Fleming and Marianne Dunbar Fleming (née Alexander). He had a sister named Thelma. Fleming lived with his family at Bellevue Hill, Sydney, and was a traveller.

On 4 January 1941, Fleming enlisted to the Second Australian Imperial Force as an officer at Sydney. He later transferred to the Royal Australian Air Force (RAAF) and served throughout the Middle East. His duties involved the development of food processing and dehydration equipment for use in the RAAF. Upon his discharge on 24 May 1946, Fleming had the rank of flying officer.

After the war, Fleming lived in Sydney and worked as an engineer. He travelled extensively, and was married several times.

Bruce Warren Fleming died on 1 October 1986 at the age of 71. He was buried at Waverly Cemetery, Sydney.