Stadium: Court 4 Round: 26 Ground: Clay
| ITF M25 Poznan | 2021/08/25 08:00 | Calvo Barcelo, Fermin v Felix Gill | 3-6,6-7 |
| ITF - M15 Doboj | 2021/07/15 08:00 | Zsombor Piros v Felix Gill | 7-5,6-7,6-2 |
| ITF - M15 Doboj | 2021/07/14 08:30 | Felix Gill v Aleksandar Mihailovic | 6-1,6-4 |
| ITF M15 Sofia | 2021/07/06 07:00 | Hanwen Li v Felix Gill | 6-4,2-6,6-3 |
| Wimbledon, London, Great Britain | 2021/06/23 13:15 | Felix Gill v Marc Polmans | 6-7,2-6 |
| Wimbledon, London, Great Britain | 2021/06/22 12:40 | Petrovic, Danilo v Felix Gill | 5-7,6-7 |
| Challenger Nottingham Qual | 2021/06/13 10:00 | Felix Gill v Alex Bolt | 6-7,4-6 |
| ITF M15 Novomoskovsk | 2021/06/03 10:00 | Felix Gill v Vidal Azorin, Jose Fco | 3-6,3-6 |
| ITF M25 Poznan | 2021/08/25 10:00 | Harry Wendelken v Soares Klier, Gilbert | 3-6,6-4,6-2 |
| ITF M25 Poznan | 2021/08/24 16:10 | Harry Wendelken v Calvo Barcelo, Fermin | 6-2,6-3 |
| ITF M25 Poznan | 2021/08/24 08:00 | Harry Wendelken v Jesse De Jager | 6-1,6-3 |
| ITF M25 Poznan | 2021/08/22 08:00 | Harry Wendelken v Vojtech Vlkovsky | 6-3,6-4 |
| ITF M15 Lodz | 2021/08/18 10:05 | Alejo Lorenzo Lingua Lavallen v Harry Wendelken | 6-2,4-6,6-4 |
| ITF M15 Lodz | 2021/08/16 11:30 | Harry Wendelken v Gajewski, Kamil | 6-3,6-7,10-7 |
| ITF M15 Lodz | 2021/08/16 08:00 | Harry Wendelken v Borkowski, Mikolaj | 6-0,6-3 |
| ITF M15 Gdynia | 2021/08/10 08:00 | Johnson, Luke v Harry Wendelken | 6-3,6-7,10-5 |