Byrne opened his scoring account for Leinster by crossing the whitewash on only his second ever start, versus Zebre on 12 February 2016.

[3] It was announced in March 2022 that Byrne had signed for Connacht alongside teammates Peter Dooley and Josh Murphy for 2022/2023 season.

He played different sevens championships to gain promotion to the 2017 Grand Prix Series.

On 26 October 2017, Byrne was named in the extended Ireland national rugby union team for the Autumn internationals.

[6] He made his debut against Argentina on 25 November 2017, starting as a winger and ending the game as a centre.