In January 2008 Byrne departed UCD to sign for newly formed League of Ireland First Division side Sporting Fingal where he also took up the position as Marketing Manager for the club.

Prior to the start of the 2011 season doubts began to surface over the financial viability of Sporting Fingal due to the withdrawal of backer Gerry Gannon.

[4] Byrne scored an incredible 40 yard free kick against Athlone Town in a 7–2 win, during a pre-season friendly.

He continued his pre-season form into the start of the season in competitive games, setting up Kenny Browne to score a header against Bangor Celtic in the Leinster Senior Cup and Shane McFaul's winner against Drogheda United on the opening day of the 2013 League of Ireland season in front of Republic of Ireland manager Giovanni Trapattoni.

He scored again four days later live on RTÉ when Pats beat champions Sligo Rovers 2–0 to end their 100% record in the league.

On the expiry of his Shelbourne contract, Byrne signed an 18-month deal with NIFL Premiership club Glenavon, taking effect from January 2020.