Harrison is a product of the Tranmere Rovers youth system, having joined the side as a 13 year old, he made his first team debut in 2001 at home against Wigan Athletic. He went on to make 125 appearances for Tranmere before joining Rotherham United in 2007 where he made an additional 188 Football League appearances. In June 2012, it was announced that Harrison had rejoined Tranmere and the following summer he joined Chester FC where he made 29 appearances before signing for The Nomads in January 2015.

Harrison made his debut in a 1-0 victory over Bala Town.

Since joining the club, Harrison has gone on to be a regular fixture in the side, playing in the club's four Europa League campaigns and the Scottish Challenge Cup.

During his time at Deeside, Harrison has picked up silverware in the form of the JD Cymru Premier, JD Welsh Cup and also the Nathaniel MG Cup.