Previously a junior pool champion, O'Connor qualified for the snooker main draw as an amateur at the 2014 Wuxi Classic, then faced Neil Robertson at the 2014,[1][2] and Mark Selby at the 2015 UK Championship.

[4] Ahead of the 2018–19 season, O'Connor defeated Brandon Sargeant 4–1 and then Oliver Brown 4–0 to secure a two-year professional tour card for the first time at the 2018 EBSA Play-Offs at the English Institute of Sport in Sheffield.

[6] In February 2019, he defeated top 10 players Kyren Wilson, Ding Junhui and John Higgins en route to his first ranking event semi-final at the Welsh Open,[7] eventually losing 6–2 to Stuart Bingham.

[10] In December 2022, O'Connor reached his first ranking final at the 2022 Scottish Open, defeating Zhao Xintong, Ding Junhui, Mark Williams, Ricky Walden and Neil Robertson throughout the tournament.

[13] In February 2023, O'Connor made it to the quarter-finals of the Welsh Open,[14] but lost 5–4 to Pang Junxu,[15] then he defeated number one seed Mark Allen at the Players Championship,[16] before bowing out to Ali Carter at the semi-final stage.