Gary was a product of the Sligo Rovers under age system and made his first senior appearances for the club in 2004, as well as making his full U18 international debut for Ireland. He left Sligo at the end of the 2008 season and signed for Longford Town, scoring four goals from midfield during an unimpressive campaign by the Midlanders.

At the end of 2009 Gary was released by Longford and was signed by Sean Connor at Galway United in February 2010 after impressing in a number of trial games. He made 30 league appearances that year, scoring three times but was released amid financial turmoil in June 2011.

One month later, in July 2011, Gary signed for Peter Hutton at Finn Harps and made 9 league appearances over the latter half of the 2011 season. But in January 2012 Gary crossed the border to join Irish League side Ballinamallard United. He returned to the LoI in February 2013 when he signed for Johnny Glynn at Mervue United, making his debut for the club in an EA Cup win over Cockhill Celtic on 1 March 2013. He scored one league goal in his time at Fahy's Field, from the penalty spot in a 4-1 win over Wexford Youths and made 23 league appearances in what would be Mervue's final season as a League of Ireland club.

On 1 February 2014 Gary signed for Alan Mathews at Bray Wanderers. He made just 5 league appearances for the Seagulls that season and left the club in the autumn of 2014. He joined Bluebell United shortly after.