Born in Dalby, Queensland, McGahan was the ninth of ten children and grew up on a wheat farm. His schooling was at St Columba's and St Mary's colleges in Dalby, and then Marist College Ashgrove in Brisbane. He commenced an Arts degree at the University of Queensland, but dropped out halfway through, in 1985, to return to the family farm, and to commence his first novel - which was never published. He then spent the next few years working in a variety of jobs, until 1991, when he wrote his first published novel, Praise.
