Dormer was born of Queensland.
He was posted from No 61 OTU to the Middle East in January 1942 and served in No 127 Squadron from May 1942. He was severely wounded in action and made PoW by the Italians on the 3rd November 1942. He was liberated and returned to Egypt in April 1943, and sent home to Australia in June of that year.
Dormer was discharged from the RAAF in January 1944 for medical reasons.