John Tom Henry Grainger was born on 22 July 1908 at Ipswich, Queensland to parents William Grainger and Edith Grainger (née Wilcock). He had two sisters, and lived with his family at Manly, Queensland. Grainger became a painter like his father. He joined his local militia unit in December 1929, but was discharged March 1930 when he was convicted of detaining mail. Grainger married Charlotte Fowler McGregor on 30 November 1937, and they lived at Highgate Hill, Queensland.

Grainger enlisted to the Royal Australian Air Force (RAAF) at Laverton, Victoria on 26 February 1940. He trained to be a RAAF cook at William Angliss Food Trade School, Melbourne, in 1941. By late 1943, he was serving in New Guinea as a cook. Grainger was discharged on 26 November 1945.

After the war, Grainger lived with Charlotte and raised a family at Manly West, Queensland. He initially worked as a cook, but had returned to his work as a painter by 1954. By 1963, Grainger had become a steward.

John Tom Henry Grainger died in March 2001, at the age of 92.