[1] He is a product of the youth system at Middlesbrough, where he made a number of appearances during the 1997-98 promotion season under Bryan Robson.
However, he did play the full match as the club sealed promotion with a 4–1 final day win over Oxford United.
In January 2002, he suffered a double compound fracture in his left leg whilst playing for the club's reserves against Reading.
[9] On 26 May 2017, Harrison was appointed as manager of newly relegated National League club Hartlepool United.
[12] On 23 May 2018, Harrison was appointed as manager of Bangor City following their relegation from the Welsh Premier League after failing to obtain a tier one license.
[14] In October 2018, Harrison joined the coaching staff at Connah's Quay Nomads following his departure from Bangor City.