Ivan Southall was born in Melbourne, Victoria. His father died when Ivan was 14, and he and his brother Gordon were raised by their mother. He went to Mont Albert Central School (where he wrote the first of his "Simon Black" stories) and later Box Hill Grammar, but was forced to leave school early, and became an apprentice process engraver. He joined the Royal Air Force in Britain, and was decorated with the Distinguished Flying Cross for his role in sinking a German U-boat, U-385, in the Bay of Biscay in 1944. He returned to Australia with his English bride, Joy Blackburn. Their youngest daughter was born with Down syndrome.