Manchester City Byrne started playing football with
St Kevin's Boys at the age of five and moved to England to join
Manchester City at the age of 15. In the 2014–15 season Byrne scored six goals in eight
UEFA Youth League games for Manchester City under-19. After missing the first six weeks of the season due to an ankle injury picked up in pre-season, Byrne made his professional debut on 19 September in a match against
FC Twente.
Blackburn Rovers loan On 29 June 2016, Byrne joined
EFL Championship club
Blackburn Rovers. He went on to make four league appearances for the club before Blackburn cancelled his season long loan on 6 January 2017.
Wigan Athletic Later in January 2017, Byrne joined Wigan Athletic for an undisclosed fee, signing a three-and-a-half-year deal. He made his debut for the club as a second-half substitute in a 3–2 victory over Rotherham on 8 April 2017.
Oldham Athletic On 15 January 2018, Byrne signed for Oldham Athletic for an undisclosed fee on a two-and-a-half-year deal. He was suspended by the club for an undisclosed, off the field incident, and subsequently released by Oldham Athletic on 31 August 2018, despite fan protests.
Kilmarnock Soon after his release from Oldham, it was confirmed that Byrne had signed for
Scottish Premiership side
Kilmarnock on a one-year deal.
Shamrock Rovers On 7 December 2018, Byrne joined
League of Ireland Premier Division club
Shamrock Rovers. His first goal for the club was a spectacular strike in a 3–0 home win over
Sligo Rovers on 15 March. After several strong performances Byrne was named Premier Division Player of the Month for March and again for July. He scored once and assisted five times in Rovers'
Europa League ties against
SK Brann and
Apollon Limassol.
APOEL On 4 January 2021, Byrne moved to Cypriot club
APOEL making five appearances and failing to score, struggling with a back injury. On 24 September 2021, Byrne left APOEL by mutual consent.
Return to Shamrock Rovers It was announced on 19 November 2021, that Byrne would return to
Shamrock Rovers on a contract beginning in January 2022.
Dubai Irish loan On 30 August 2025, Byrne was loaned out to
UAE Third Division League side Dubai Irish on loan until December, following a training ground row with Rovers manager
Stephen Bradley that saw him frozen out from the team in the weeks leading up to the move. On 17 October 2025, he scored his first goal for the club in a 3–1 win away to Emerald Club. After returning to Rovers from his loan spell, he deemed the loan a success in gaining regular game time and allowing him to work on his fitness to return to his parent club in a better place. ==International career==