Born in Kilkenny,[3] O'Connor first joined the Southampton academy in 2015. He was contracted to the club until June 2021 having signed a two-year contract extension in January 2019.[4]
On 29 August 2019 O'Connor signed for League One side Gillingham on loan until January 2020.[5][6] He made his debut for the club two days later in a 5–0 league win over Bolton Wanderers.[7] His first league goal for the club was an 83rd-minute equaliser against Bristol Rovers on 17 September 2019.[8]
On 31 December 2019 his loan with the club was extended until the end of the 2019–20 season.[9] He returned to Southampton at the conclusion of the 2019–20 season, having made 32 appearances for the Kent side in all competitions.[10] On 29 September 2020 he re-signed for Gillingham on loan for the 2020–21 season.[11]
Burton Albion
On 23 June 2021 it was announced that he would sign a two-year deal for League One side Burton Albion following the expiry of his Southampton contract.[12]
Wrexham
He moved to Wrexham of the National League for an undisclosed fee in January 2022,[13][14] making his debut for the Welsh side in a 1–0 away league defeat to Torquay United.[15] On 9 July 2024 he signed a three-year extension until 2027.[16]
International career
O'Connor was called up to the Republic of Ireland U19 squad in February 2017.[17] He made his debut as a substitute in a 1–0 win over Portugal.[18]