Chaplain began his career in the Rangers youth set-up before moving on to Ayr United in 2000. He made 91 starts and scored 11 goals in his 5 seasons at the club before being released and signing for Albion Rovers. His biggest success for Rovers came in the 2006–07 season when he scored 18 league goals and won the SPFA's player of the year award for the Third Division. At the end of the season, he was snapped up by Partick Thistle manager Ian McCall.
After being released by Partick Thistle in the summer of 2009, Chaplain dropped a division to sign for Dumbarton. He signed for a second stint with Albion Rovers in January 2011.
Chaplain left Albion Rovers in summer 2012 to join Third Division side Annan Athletic but could not resist a move back to Cliftonhill in May 2013.