| WTA - Montevideo | 11/22 21:30 | 25 | Guillermina Grant v Ipek Oz | 2-6,1-6 | |
| Billie Jean King Cup | 07/30 15:25 | 2 | Romina Ccuno v Guillermina Grant | 3-6,3-6 | |
| Billie Jean King Cup | 07/28 16:30 | 2 | Guillermina Grant v Ariana Rahmanparast | 6-0,6-0 | |
| Billie Jean King Cup | 07/27 15:20 | 2 | Guillermina Grant v Junmoke James | 6-2,6-0 | |
| Billie Jean King Cup | 07/26 16:30 | 2 | Guillermina Grant v Natalie G E Sanchez | 7-6,6-3 | |
| Billie Jean King Cup | 07/25 15:15 | 2 | Guillermina Grant v Hannah Chambers | 6-3,6-3 | |
| WTA - Montevideo | 11/16 20:15 | 25 | Guillermina Grant v Maria Lourdes Carle | 6-7,2-6 | |
| Billie Jean King Cup | 06/26 19:00 | - | Charlotte Roemer v Guillermina Grant | 7-5,3-6,6-3 | |
| Billie Jean King Cup | 06/25 15:00 | - | Sydney Clarke v Guillermina Grant | 2-6,3-6 | |
| Billie Jean King Cup | 06/24 17:10 | - | Guillermina Grant v Ariana Rahmanparast | 6-3,6-2 | |
| 2019 Fed Cup | 04/19 14:00 | - | Melissa Morales v Guillermina Grant | 7-5,5-7,6-4 | |
| 2019 Fed Cup | 04/18 14:00 | - | Isid Hernandez v Guillermina Grant | 4-6,1-6 |
Guillermina Grant (born 22 June 2002) is a Uruguayan tennis player, who played at the Uruguay on the Fed Cup since 2017.
Grant has a career-high ITF juniors ranking of 31, achieved on 2 March 2020.
In December 2020, Grant signed with the Georgia Bulldogs college team for the 2021-22 season.