Bowen was born on 26 May 1911 in Summerland, British Columbia, Canada. He was the son of Dorothy Joan (née King) and Otway Percival Bowen. His parents, both born in England, were apple farmers.[1]
Bowen and his parents moved to Australia shortly after his birth. They initially settled on a sheep farm in Gunnedah, New South Wales, but following a drought moved to Sydney where his father worked as an accountant. Bowen was sent to school in England from 1919 to 1921 with financial assistance from an aunt. After returning to Australia he attended The King's School, Parramatta, from 1922 to 1927. He subsequently matriculated to the University of Sydney, graduating Bachelor of Arts in 1931 and Bachelor of Laws in 1934. He served his articles of clerkship with Sly and Russell in Sydney and was called to the bar in 1936. He practised "widely across fields that included divorce, probate, and inheritance".[1]
In 1947, Bowen married Eileen Mullins, a nurse, with whom he had three daughters. He was widowed in 1983 and in 1984 remarried to Ermyn Winifred Krippner (née Hookway; 1911–1995), a widowed schoolteacher who had been principal of Burwood Girls High School (1961–1976) and whom he had first met while they were both students at Sydney University.[1][6]