King began his career at Plymouth Argyle, playing there for two seasons.
In 2008 he returned to Ireland to play for the Sligo Rovers 'A' side.
2009 saw him move to League of Ireland First Division club, Longford Town. He ended a successful season there by picking up the club's player of the season award.
On the 4th of February 2010, King was unveiled by Galway United as their latest addition to their 2010 League of Ireland Premier Division squad.
In February 2011, King signed for Mervue United. King scored on his debut for the club against local rivals Salthill Devon in the opening game of the season.
The 2011 season was a write off for Tom after injury on the pitch,but off the pitch he began to make a name for himself. The Sun reported of a leaked sex tape with an unnamed Fair City actress.