He was the son of Bertha (née Widler) and William John Turnbull; his mother was born in Singapore, while his father was an Australian journalist working on the North China Daily News.

[3] Turnbull's father died when he was a boy and his mother remarried to Enos Soren Thellefsen, a Danish diplomat in the Shanghai International Settlement.

[3] In 1942, Turnbull enlisted in the Australian Imperial Force (AIF), having previously spent six years in the Melbourne University Regiment.

[3] Turnbull became involved in politics through his advocacy for compulsory tuberculosis screening, which the Australian Labor Party (ALP) supported.

As health minister, Turnbull introduced a number of initiatives including tuberculosis screening, anti-cancer clinics and subsidised pap tests, and recruited general practitioners from overseas to fill a shortage in regional areas.

[3] Turnbull resigned from cabinet in June 1958 after being charged with accepting a bribe from George Fitzpatrick, a Sydney businessman, in relation with a lotteries licence.

The ALP caucus unanimously voted for Turnbull to be removed from the ministry, however he refused to resign and Reece had to instruct administrator Stanley Burbury to revoke his appointment.

[3] The following year, he announced plans to contest the 1975 Bass by-election, prompted by the resignation of deputy prime minister Lance Barnard.

[16] However, he ultimately decided not to contest the seat, on the grounds that he believed a double dissolution was likely and he did not have the funds to run multiple campaigns in a short amount of time.