George Hermon Gill was educated in London and Yorkshire. He went to sea as an apprentice at the age of fifteen, and four years later, in 1914, sailed to Australia. Throughout World War I, Gill served at sea with the Aberdeen Line, becoming second officer and earning his master-mariner's certificate by 1921.
In 1922, Gill emigrated to Melbourne, where he worked for the Commonwealth Government Line of Steamers. He married Australian artist Esther Paterson in 1923, and resigned in 1929 to take her to visit England. There, he worked as a freelance journalist, writing many pieces about the sea, before becoming a reporter on the Star in 1933.
Returning to Australia, Gill worked in various posts in the Australian Navy, including the Examination and Naval Control Services and the Naval Intelligence Division, where he managed the historical records section and was the Publicity Censorship Liaison Officer. During this time, Gill edited a series of books on the Australian Navy, and wrote an official naval history of Australia in World War II. He edited the journal Navy from 1947 onwards, and also edited the suburban newspaper the South Melbourne Record in the 1950s.
Gill was awarded an M.B.E. in 1943 and retired in 1953.