Head to Head
| German Masters 2017 | 2016/12/08 10:00 | Mark Allen v Sean O'Sullivan | 5-4 |
Home History
| European Masters Qualifiers | 2018/08/18 15:00 | Mark Allen v David Lilley | 4-3 |
| World Open | 2018/08/08 11:30 | Mark Allen v Jack Lisowski | 1-5 |
| World Open | 2018/08/07 06:30 | Mark Allen v Lyu Haotian | 5-1 |
| Riga Masters 2018 | 2018/07/28 16:50 | Ricky Walden v Mark Allen | 4-2 |
| Riga Masters 2018 | 2018/07/28 12:00 | Mark Allen v Ali Carter | 4-2 |
| Riga Masters 2018 | 2018/07/27 15:10 | Mark Allen v Peter Lines | 4-3 |
| World Open | 2018/07/06 18:00 | Mark Allen v Peter Lines | 5-2 |
| Riga Masters 2018 | 2018/07/04 18:00 | Mark Allen v Daniel Wells | 4-2 |
Away History
| European Masters Qualifiers | 2018/08/17 12:00 | Joe Perry v Sean O'Sullivan | 4-0 |
| Indian Open 2018 | 2018/08/16 12:00 | Mark Davis v Sean O'Sullivan | 4-1 |
| World Open | 2018/07/08 13:30 | Noppon Saengkham v Sean O'Sullivan | 5-2 |
| Riga Masters 2018 | 2018/07/04 09:00 | Liam Highfield v Sean O'Sullivan | 4-0 |
| World Championship | 2018/04/14 09:00 | Yu Delu v Sean O'Sullivan | 10-8 |
| Gibraltar Open 2019 | 2018/03/10 15:10 | Zhang Yong v Sean O'Sullivan | 4-2 |
| Welsh Open | 2018/02/26 09:45 | Jackson Page v Sean O'Sullivan | 4-3 |
| Snooker Shoot-Out | 2018/02/11 14:10 | Sean O'Sullivan v Gerard Greene | 0-1 |