Delaney joined the Erin's Own club at a young age and played in all grades at juvenile and underage levels before eventually joining the club's senior team in the Kilkenny Senior Championship.
On 6 July 2014, Delaney lined out at full-back when Kilkenny faced Dublin in the Leinster final. He collected a second winners' medal - his first on the field of play - following a 2-19 to 2-10 victory.[4] Delaney retained the full-back position for the All-Ireland final against Limerick on 7 September 2014 and ended the game with a winners' medal following the 2-17 to 0-19 victory.[5]
Delaney was added to the Kilkenny under-21 panel prior to the start of the 2015 Leinster Championship. He made his first appearance in that grade on 2 June 2015 when he lined out at right corner-back in a 4-12 to 2-16 defeat of Dublin. On 8 July 2015, Delaney was switched to full-back when Kilkenny suffered a 4-17 to 1-09 defeat by Wexford in the Leinster final.[6]
On 5 July 2017, Delaney won a Leinster Championship medal after lining out at full-back in the 0-30 to 1-15 defeat of Wexford in the final.[7] On 9 September 2017, he was again at full-back for the All-Ireland final against Limerick. He ended the game on the losing side following the 0-17 to 0-11 defeat.[8] Delaney ended the season by being named in the full-back position on the Bord Gáis Energy Team of the Year.[9]
Intermediate
Delaney was added to the Kilkenny intermediate team in advance of the 2016 Leinster Championship. On 13 July 2016, he won a Leinster Championship when he lined out at centre-back in Kilkenny's 3-14 to 2-14 defeat of Wexford in the final.[10] Delaney retained his position at centre-back for the All-Ireland final against Clare on 6 August 2016 and ended the game with a winners' medal after a 5-16 to 1-16 victory.[11]
Senior
Delaney was added to the Kilkenny senior team as a member of the training panel at the start of the 2016 season. He was a Leinster Championship medal on 3 July 2016 as a member of the extended panel following Kilkenny's 1-26 to 0-22 defeat of Galway in the final.[12] Delaney was again a member of the extended panel when Kilkenny suffered a 2-29 to 2-20 defeat by Tipperary in the All-Ireland final on 4 September 2016.[13]
Delaney made his first appearance for the Kilkenny senior team on 18 February 2018 when he lined out at right wing-back in a 1-20 to 1-12 defeat of Waterford in the National League.[14] On 8 April 2018, he was again at right wing-back when Kilkenny faced Tipperary in the National League final. He ended the game with a winners' medal following the 2-23 to 2-17 victory.[15] On 1 July 2018, Delaney was selected amongst the substitutes when Kilkenny drew 0-18 apiece with Galway in the Leinster final.[16] He was again named on the bench for the replay a week later, however, Kilkenny suffered a 1-28 to 3-15 defeat.[17]
Delaney was a regular at full-back during the 2019 National League and looked likely to retain that position for the Leinster Championship.[18] In April 2019, it was confirmed that he would be sidelined for up to two months after breaking the tibia bone in his leg.[19] Delaney was an unused substitute when Kilkenny suffered a 1-23 to 0-23 defeat by Wexford in the Leinster final on 30 June 2019.[20]