Fox was raised in Birkenhead, where he attended the Glenda Jackson youth theatre. Paul had roles in Hearts and Minds and Children's Ward before winning the role of Will Cairns in Emmerdale. Ten months after his final appearance as Will Cairns, Fox made his debut in Coronation Street as Mark Redman. Between 2003 and 2007 Fox appeared in The Royal as Dr Jeff Goodwin. He has also had minor roles in Doctors and Casualty.