Head to Head
| 2023 The Masters | 2023/01/12 13:05 | Mark Williams v Ronnie O'Sullivan | 6-5 |
| 2022 Tour Championship | 2022/03/30 12:00 | Ronnie O'Sullivan v Mark Williams | 10-9 |
| 2021 Open de Gales | 2021/02/20 19:10 | Mark Williams v Ronnie O'Sullivan | 1-6 |
| Championship League Snooker | 2021/02/11 15:45 | Ronnie O'Sullivan v Mark Williams | 1-3 |
| 2020 Campeonato Mundial | 2020/08/11 18:00 | Mark Williams v Ronnie O'Sullivan | 10-13 |
| 2019 Gibraltar Open | 2017/11/16 11:30 | Ronnie O'Sullivan v Mark Williams | 5-1 |
| 2019 Gibraltar Open | 2016/12/02 19:00 | Mark Williams v Ronnie O'Sullivan | 2-6 |
| Championship League Snooker | 2016/01/04 12:00 | Ronnie O'Sullivan v Mark Williams | 3-2 |