Warwick McFadyen grew up in the Hunter Valley, New South Wales, and attended Kotara High School in Newcastle, where he completed his schooling in 1976. In 1977 he commenced a cadetship at the Newcastle Morning Herald. He later moved to Melbourne and worked as a journalist with the Melbourne Age.
McFadyen is a relative of poet and children's author Ella McFadyen (q.v.). Warick McFadyen's great-grandfather's brother was the husband of Ella McFadyen's mother.
