| ITF Cameroon F1 | 11/27 11:40 | 25 | Arpit Sharma v Guillermo Olaso | Cancelled | |
| ITF Finland F4 | 11/12 12:20 | 25 | Christopher Heyman v Guillermo Olaso | Cancelled | |
| ITF Mozambique F1 | 11/06 08:25 | 25 | Guillermo Olaso v Lluis Dolz | Cancelled | |
| ITF Vietnam F4 | 10/24 02:30 | 25 | Nitin Kumar Sinha v Guillermo Olaso | Cancelled | |
| ITF Spain F31 | 10/10 10:00 | 25 | Maxime Mora v Guillermo Olaso | Cancelled | |
| ITF Lebanon F2 | 10/02 13:00 | 25 | Guillermo Olaso v Jaroslav Pospisil | Cancelled | |
| ITF Lebanon F1 | 09/29 13:00 | 28 | [400] Alexandre Muller v Guillermo Olaso [447] | 4-6,6-3,6-0 | |
| ITF Lebanon F1 | 09/28 13:00 | 27 | Guillermo Olaso v Edoardo Eremin | 6-1,6-4 | |
| ITF Lebanon F1 | 09/27 13:00 | 26 | Guillermo Olaso v Hasan Ibrahim | 6-2,6-4 | |
| ITF Lebanon F1 | 09/26 14:35 | 25 | Guillermo Olaso v Jaroslav Pospisil | 6-1,6-1 | |
| ITF Germany F8 | 07/19 11:35 | 26 | [435] Orlando Luz v Guillermo Olaso [375] | 7-6,6-0 | |
| ITF Germany F8 | 07/18 11:25 | 25 | Lucas Gerch v Guillermo Olaso | 2-6,3-6 | |
| ITF Spain F16 | 06/27 18:45 | 26 | Evan Hoyt v Guillermo Olaso | 4-6,6-2,6-4 | |
| ITF Spain F16 | 06/26 19:40 | 25 | Antonio Cembellin Prieto v Guillermo Olaso | 3-6,3-6 | |
| ITF France F10 | 06/20 12:20 | 26 | Guillermo Olaso v Maxime Tchoutakian | Retired | |
| ITF France F10 | 06/19 11:15 | 25 | Guillermo Olaso v Eduard Guell | 4-6,6-3,7-6 | |
| Challenger Poznan Qual | 06/04 13:30 | 54 | [383] Jeremy Jahn v Guillermo Olaso [361] | 6-7,6-1,6-2 | |
| Challenger Poznan Qual | 06/04 08:00 | 46 | Ronald Slobodchikov v Guillermo Olaso | 4-6,6-3,1-6 | |
| Challenger Poznan Qual | 06/03 09:25 | 45 | [388] Juan Pablo Ficovich v Guillermo Olaso [361] | 4-6,2-6 | |
| Challenger Busan Qual | 05/14 02:00 | 54 | [346] Rubin Statham v Guillermo Olaso [359] | 6-4,6-2 | |
| Challenger Busan Qual | 05/13 02:00 | 46 | Thomas Fancutt v Guillermo Olaso | 1-6,5-7 | |
| Challenger Busan Qual | 05/12 01:00 | 45 | Jae Hwan Kim v Guillermo Olaso | 0-6,5-7 | |
| Challenger Glasgow | 05/04 09:30 | 27 | [104] Lukas Lacko v Guillermo Olaso [386] | 6-2,6-3 | |
| Challenger Glasgow | 05/02 13:50 | 26 | [386] Guillermo Olaso v Lloyd Glasspool [477] | 6-4,6-3 | |
| Challenger Glasgow | 04/30 11:15 | 25 | [330] Evgeny Karlovskiy v Guillermo Olaso [386] | 6-7,3-6 | |
| ITF Spain F10 | 04/24 12:35 | 25 | Guillermo Olaso v Adrien Bossel | Retired | |
| ITF Spain F9 | 04/19 14:00 | 26 | [383] Guillermo Olaso v Steven Diez [330] | 7-6,1-6,5-7 | |
| ITF Spain F9 | 04/17 09:25 | 25 | Guillermo Olaso v Adrien Bossel | 6-2,6-4 | |
| Challenger Alicante Qual | 03/31 09:55 | 45 | [289] Carlos Gomez-Herrera v Guillermo Olaso [420] | 2-6,7-6,7-5 | |
| Challenger Marbella Qual | 03/24 19:25 | 45 | [314] Federico Gaio v Guillermo Olaso [420] | 7-5,7-6 |