| ITF Norway F1 | 10/19 12:10 | 26 | Elmar Ejupovic v Hunter Callahan | 5-7,3-6 | |
| ITF Norway F1 | 10/18 12:00 | 25 | Hunter Callahan v Jonathan Mridha | 6-4,2-6,6-2 | |
| ITF USA F30 | 09/29 18:20 | 26 | Takanyi Garanganga v Hunter Callahan | 6-2,1-6,6-4 | |
| ITF USA F30 | 09/27 19:10 | 25 | Hunter Callahan v Elmar Ejupovic | 7-5,6-1 | |
| ITF USA F29 | 09/21 17:00 | 25 | Hunter Callahan v Lucas Gomez | 3-6,6-7 | |
| ITF USA F29 | 09/19 18:30 | 60 | Hunter Callahan v Hunter Johnson | 6-3,6-1 | |
| ITF USA F29 | 09/18 19:30 | 60 | Hunter Callahan v Alessandro-D Ventre | 6-4,6-3 | |
| ITF USA F29 | 09/17 00:30 | 60 | Hunter Callahan v Errol Smith | 6-3,7-5 | |
| ITF USA F28 | 09/13 21:45 | 25 | Hunter Callahan v Ty Trombetta | 2-6,4-6 | |
| ITF USA F27 | 08/09 14:00 | 25 | Marc Polmans v Hunter Callahan | 6-3,6-3 | |
| ITF USA F27 Qual | 08/07 13:30 | 62 | Hunter Callahan v Nils Ellefsen | 6-3,6-2 | |
| ITF USA F26 | 08/03 15:00 | 25 | Evan King v Hunter Callahan | 6-3,7-5 | |
| ITF USA F26 Qual | 08/01 16:50 | 62 | Hunter Callahan v Felix Corwin | 7-5,7-6 | |
| ITF USA F26 Qual | 07/31 16:30 | 62 | Hunter Callahan v Mwendwa Mbithi | 6-2,6-1 | |
| ITF USA F26 Qual | 07/30 17:00 | 62 | Hunter Callahan v Stefan Frljanic | Retired | |
| ITF USA F22 | 06/28 14:00 | 25 | Hunter Callahan v Thai-Son Kwiatkowski | 4-6,1-6 | |
| ITF USA F20 | 06/23 21:15 | 26 | Nathan Pasha v Hunter Callahan | 6-3,7-6 | |
| ITF USA F20 | 06/22 19:30 | 25 | Andrew Carter v Hunter Callahan | 2-6,1-6 | |
| ITF USA F19 | 06/16 17:35 | 26 | Farris Fathi Gosea v Hunter Callahan | 7-6,7-5 | |
| ITF USA F19 | 06/14 16:35 | 25 | Hunter Callahan v Daniel Garza | 7-5,6-4 | |
| ITF Italy F11 | 05/18 10:40 | 25 | Hunter Callahan v Cristian Carli | 4-6,6-3,5-7 | |
| ITF Italy F11 Qual | 05/16 14:35 | 44 | Hunter Callahan v Luca Tomasetto | 6-2,3-6,6-3 | |
| ITF Italy F11 Qual | 05/16 09:45 | 44 | Hunter Callahan v Alessandro Cortegiani | 6-4,6-0 | |
| Challenger Rome Qual | 04/30 11:35 | 46 | Marton Fucsovics v Hunter Callahan | 6-1,6-3 | |
| Challenger Rome Qual | 04/30 09:00 | 45 | Lorenzo Camilli v Hunter Callahan | 0-6,0-6 | |
| ITF Greece F6 | 04/27 07:00 | 25 | Aaron Addison v Hunter Callahan | 6-4,7-6 | |
| ITF Greece F6 | 04/25 09:15 | 62 | Hunter Callahan v Pavel Krainik | 3-6,7-5,6-3 | |
| ITF Greece F5 | 04/21 10:15 | 26 | Hunter Callahan v Lloyd Glasspool | 6-7,2-6 | |
| ITF Greece F5 | 04/20 10:10 | 25 | Hunter Callahan v Raymond Sarmiento | 4-6,7-6,7-5 | |
| ITF Greece F5 | 04/18 08:40 | 62 | Martin Beran v Hunter Callahan | 6-3,3-6,6-7 |