| ITF M15 - Monastir | 11/25 13:00 | 44 | Guillaume Dermiens v Mattia Frinzi | 6-7,1-6 | |
| ITF M15 - Monastir | 11/25 08:00 | 44 | Tadija Radovanovic v Guillaume Dermiens | 4-6,2-6 | |
| ITF M15 - Monastir | 11/24 08:30 | 44 | Nicolo Inserra v Guillaume Dermiens | 2-6,3-6 | |
| ITF M15 - Monastir | 11/20 13:20 | 25 | Clement Geens v Guillaume Dermiens | 6-0,6-0 | |
| ITF M15 - Monastir | 11/18 13:30 | 44 | Miles Jones v Guillaume Dermiens | 3-6,5-7 | |
| ITF M15 - Monastir | 11/18 08:00 | 44 | Skander Ben Fraj v Guillaume Dermiens | 2-6,2-6 | |
| ITF M15 - Monastir | 11/17 10:00 | 44 | Guillaume Dermiens v Sergei Pogosian | 6-2,6-3 | |
| ITF M15 Getafe Madrid | 10/14 07:30 | 44 | Clement Chidekh v Guillaume Dermiens | 4-6,6-3,10-5 | |
| ITF M15 Getafe Madrid | 10/13 08:45 | 44 | Guillaume Dermiens v Conor Berg | 6-4,6-2 | |
| ITF M15 - Sharm El Sheikh | 10/02 08:00 | 25 | Guillaume Dermiens v Vitaliy Sachko | 3-6,2-6 | |
| ITF M15 - Sharm El Sheikh | 10/01 08:00 | 44 | Guillaume Dermiens v Charles Minc | 7-5,4-6,12-10 | |
| ITF M15 - Lambermont | 08/21 10:55 | 25 | Guillaume Dermiens v Dan Added | 5-7,2-6 | |
| ITF M15 Koksijde | 08/13 13:00 | 25 | Guillaume Dermiens v Ugo Blanchet | 0-6,6-2,5-7 | |
| ITF M15 Brussels | 07/31 12:00 | 25 | Guy Den Heijer v Guillaume Dermiens | 6-3,6-3 | |
| ITF M25 Lasne | 07/03 08:00 | 25 | Dragos Dima v Guillaume Dermiens | 6-4,6-4 | |
| ITF M25 Lasne | 07/02 11:50 | 54 | Guillaume Dermiens v Buvaysar Gadamauri | 2-6,6-3,11-9 | |
| ITF M25 Lasne | 07/01 15:55 | 54 | Dominik Recek v Guillaume Dermiens | 6-4,4-6,7-10 | |
| ITF M25 - Arlon | 06/25 11:40 | 54 | Filip Bergevi v Guillaume Dermiens | 6-3,6-3 | |
| ITF M25 - Arlon | 06/24 15:15 | 54 | Guillaume Dermiens v Arvid Nordquist | 6-1,6-4 | |
| ITF M15 - Kalmar | 05/14 08:15 | 54 | Simon Freund v Guillaume Dermiens | 6-3,4-6,10-6 | |
| ITF M15 - Kalmar | 05/13 08:15 | 54 | Olof Wiklund v Guillaume Dermiens | 6-3,5-7,2-10 | |
| ITF Czech Republic F11 Qual | 11/19 11:00 | 54 | Ondrej Krstev v Guillaume Dermiens | 6-2,6-2 | |
| ITF Tunisia F37 | 10/20 09:00 | 44 | Diego F Flores v Guillaume Dermiens | Retired | |
| ITF Belgium F9 | 08/21 09:00 | 25 | Guillaume Dermiens v Dan Added | 3-6,1-6 | |
| ITF Belgium F8 | 08/14 09:00 | 25 | Guillaume Dermiens v Alex Knaff | 1-6,4-6 | |
| ITF Belgium F7 | 08/07 09:10 | 25 | Maxime Chazal v Guillaume Dermiens | 6-1,6-1 | |
| ITF Belgium F6 Qual | 07/28 07:00 | 44 | Julien De Cuyper v Guillaume Dermiens | 6-3,0-6,6-2 | |
| ITF Belgium F5 | 07/21 11:00 | 44 | Flemming Peters v Guillaume Dermiens | 7-6,6-4 | |
| ITF Belgium F5 | 07/21 07:00 | 44 | Guillaume Dermiens v Joaquin P M Bannen | 6-2,6-2 | |
| ITF Belgium F4 | 07/14 08:30 | 44 | Jakub Wojcik v Guillaume Dermiens | 6-1,6-2 |