Stadium: Hard Court Central Round: 25 Ground: Hardcourt outdoor
| ITF - M15 Héraklion | 2021/06/02 10:55 | Marvin Moeller v March, Antonio Cayetano | 3-6,6-7 |
| Sibenik, Singles M-ITF-CRO-05A | 2021/04/20 11:05 | Marvin Moeller v Cuenin, Sean | 6-2,6-7,2-6 |
| ITF M25 Meerbusch | 2021/04/13 13:30 | Wang, Tak Khunn v Marvin Moeller | 6-4,6-3 |
| ITF M25 Biel | 2021/03/29 12:05 | Yann Marti v Marvin Moeller | 6-4,6-7,10-5 |
| ITF - M15 Poitiers | 2021/03/19 13:10 | Kyrian Jacquet v Marvin Moeller | 6-2,6-3 |
| ITF - M15 Poitiers | 2021/03/17 10:30 | Marvin Moeller v Rakotohasy, Jean-Jacques | 6-2,6-1 |
| ITF - M25 Trimbach | 2021/03/11 12:00 | Stricker, Dominic Stephan v Marvin Moeller | 6-1,6-4 |
| ITF - M25 Trimbach | 2021/03/10 09:00 | Hartmeier, Patrik v Marvin Moeller | 1-6,7-6,2-6 |
| ITF - M15 Héraklion | 2021/06/08 06:30 | Graziani, Edoardo v Griffith, William | 6-1,4-6,4-10 |
| ITF - M15 Héraklion | 2021/06/07 07:30 | Ansari, Austin Ansari v Griffith, William | 1-6,1-6 |
| ITF - M15 Héraklion | 2021/06/06 11:00 | Podzimek, Floris v Griffith, William | 1-6,1-6 |
| ITF - M15 Héraklion | 2021/06/02 11:20 | Griffith, William v Federico Arnaboldi | 3-6,7-6,3-6 |
| ITF - M15 Héraklion | 2021/06/01 06:30 | Ansari, Austin Ansari v Griffith, William | 1-6,0-6 |
| ITF - M15 Héraklion | 2021/05/31 06:30 | Cohen, Eduardo v Griffith, William | 1-6,1-6 |
| ITF - M15 Héraklion | 2021/05/30 09:00 | Wunder, Markus v Griffith, William | 4-6,2-6 |
| ITF - M15 Héraklion | 2021/05/26 08:50 | Griffith, William v Yuki Mochizuki | 4-6,4-6 |