| Season | Team | Competition | MP | G | A | Rating | ||
|---|---|---|---|---|---|---|---|---|
| 2027 | Ireland U21 | Euro U21 - Qualification | 1 | 1 | 0 | 0 | 0 | – |
| 2023 | Ireland U19 | Euro U19 - Qualification | 6 | 0 | 0 | 2 | 0 | – |
| 2021 | Ireland U19 | Friendly International | 1 | 0 | 0 | 0 | 0 | – |
| Total | 8 | 1 | 0 | 2 | 0 | – | ||
| Fecha | Desde | Hacia | Tipo | |
|---|---|---|---|---|
| - | Boston Utd | Lincoln | Return from loan | |
| - | Lincoln | Boston Utd | Loan | |
| - | Boston Utd | Lincoln | Return from loan | |
| 01 sept 2025 | Lincoln | Boston Utd | Loan | |
| 01 ago 2025 | Peterborough Sports | Lincoln | Return from loan | |
| 08 sept 2024 | Lincoln | Peterborough Sports | Loan | |
| - | Drogheda | Lincoln | Return from loan | |
| - | Lincoln | Drogheda | Loan | |
| 01 ene 2024 | Peterborough Sports | Lincoln | Return from loan | |
| - | Lincoln | Peterborough Sports | Loan | |
| - | Barwell | Lincoln | Return from loan | |
| 02 abr 2023 | Lincoln | Barwell | Loan | |
| 07 ene 2021 | Derry City | Lincoln | Transfer |
O. Gallagher career history shows progression across clubs and competitions, including club timeline, national team appearances and overall career totals.