| Season | Team | Competition | MP | G | A | Rating | ||
|---|---|---|---|---|---|---|---|---|
| 2025/2026 | Shelbourne | Champions League | 1 | 0 | 0 | 1 | 0 | – |
| 2024/2025 | Shelbourne | Conference League | 2 | 0 | 0 | 0 | 0 | 6.2 |
| Total | 3 | 0 | 0 | 1 | 0 | – | ||
| Date | From | To | Type | |
|---|---|---|---|---|
| 01 Jan 2024 | Bohemians | Shelbourne | Free agent | |
| 07 Jan 2022 | Accrington | Bohemians | Transfer | |
| 07 Jan 2021 | Morecambe | Accrington | Free agent | |
| 07 Feb 2019 | Blackpool | Morecambe | Free agent | |
| - | Dundee FC | Blackpool | Return from loan | |
| - | Blackpool | Dundee FC | Loan | |
| 07 Jan 2018 | Carlisle | Blackpool | Free agent | |
| - | Blackburn | Carlisle | Free agent | |
| 01 Aug 2017 | Accrington | Blackburn | Return from loan | |
| 08 Aug 2016 | Blackburn | Accrington | Loan | |
| - | Bury | Blackburn | Return from loan | |
| - | Blackburn | Bury | Loan | |
| 01 Mar 2016 | Rochdale | Blackburn | Return from loan | |
| - | Blackburn | Rochdale | Loan | |
| - | Barnsley | Blackburn | Return from loan | |
| - | Blackburn | Barnsley | Loan | |
| - | Accrington | Blackburn | Return from loan | |
| - | Blackburn | Accrington | Loan | |
| - | Southport | Blackburn | Return from loan | |
| 01 Sept 2014 | Blackburn | Southport | Loan |
J. O'Sullivan career history shows progression across clubs and competitions, including club timeline, national team appearances and overall career totals.