| ITF W25 - Kairo | 01/26 13:15 | 25 | Valentini Grammatikopoulou v Anastasia Nefedova | 7-5,6-7,4-6 | |
| Australian Open - Damer | 01/11 07:35 | 14 | [186] Valentini Grammatikopoulou v Asia Muhammad [225] | 3-6,2-6 | |
| ITF W60 - Traralgon | 01/05 23:00 | 26 | [216] Jodie Anna Burrage v Valentini Grammatikopoulou [183] | 7-6,7-6 | |
| ITF W60 - Traralgon | 01/04 04:55 | 25 | [208] Alexandra Ignatik v Valentini Grammatikopoulou [183] | 2-6,2-6 | |
| WTA Seoul | 12/22 05:55 | 26 | [274] Anastasia Kulikova v Valentini Grammatikopoulou [184] | 6-1,6-2 | |
| WTA Moskva | 10/16 16:05 | 14 | [133] Anna-Lena Friedsam v Valentini Grammatikopoulou [186] | 6-3,6-0 | |
| ITF W25 - Johannesburg | 09/22 07:00 | 25 | Valentini Grammatikopoulou v Elizabeth Mandlik | Cancelled | |
| ITF W25 - Johannesburg | 09/15 09:40 | 25 | Jenna Defalco v Valentini Grammatikopoulou | Retired | |
| US Open - Damer | 09/01 15:30 | 24 | [16] Elise Mertens v Valentini Grammatikopoulou [234] | 6-2,6-2 | |
| US Open - Damer | 08/30 23:15 | 23 | [234] Valentini Grammatikopoulou v Anna Blinkova [84] | 6-3,6-2 | |
| US Open - Damer | 08/27 18:50 | 19 | [243] En Shuo Liang v Valentini Grammatikopoulou [234] | 2-6,7-5,5-7 | |
| US Open - Damer | 08/26 20:55 | 15 | [234] Valentini Grammatikopoulou v Anna Kalinskaya [137] | 2-6,6-4,6-2 | |
| US Open - Damer | 08/25 19:10 | 14 | [172] Lucia Bronzetti v Valentini Grammatikopoulou [234] | 6-3,1-6,4-6 | |
| ITF W25 - Koksijde | 08/12 09:20 | 26 | [462] Magali Kempen v Valentini Grammatikopoulou [229] | 6-4,6-3 | |
| ITF W25 - Koksijde | 08/10 09:25 | 25 | [416] Victoria Bosio v Valentini Grammatikopoulou [229] | 3-6,0-6 | |
| WTA Cluj-Napoca | 08/01 13:25 | 14 | [207] Paula Ormaechea v Valentini Grammatikopoulou [267] | 7-5,6-4 | |
| ITF W25 - Telavi | 07/26 07:30 | - | [226] Tessah Andrianjafitrimo v Valentini Grammatikopoulou [267] | 5-7,4-6 | |
| ITF W25 - Telavi | 07/24 11:30 | 29 | [312] Fernanda Contreras Gomez v Valentini Grammatikopoulou [267] | 0-6,2-6 | |
| ITF W25 - Telavi | 07/24 06:00 | 28 | [411] Justina Mikulskyte v Valentini Grammatikopoulou [267] | Retired | |
| ITF W25 - Telavi | 07/23 06:30 | 27 | [448] Victoria Bosio v Valentini Grammatikopoulou [267] | 1-6,4-6 | |
| ITF W25 - Telavi | 07/21 06:00 | 26 | Elena Malygina v Valentini Grammatikopoulou | 3-6,6-4,4-6 | |
| WTA Lausanne | 07/14 08:30 | 25 | [273] Valentini Grammatikopoulou v Jasmine Paolini [87] | 3-6,6-4,5-7 | |
| WTA Lausanne | 07/12 08:30 | 19 | [273] Valentini Grammatikopoulou v Jesika Maleckova [275] | 6-3,6-7,6-2 | |
| ITF W60 - Amstelveen | 07/08 12:15 | 26 | [278] Valentini Grammatikopoulou v Suzan Lamens [371] | 6-4,2-6,1-6 | |
| ITF W60 - Amstelveen | 07/07 13:25 | 25 | [476] Ipek Oz v Valentini Grammatikopoulou [278] | 2-6,7-5,3-6 | |
| ITF W25 - Haag | 07/01 13:00 | 26 | [278] Valentini Grammatikopoulou v Arianne Hartono [351] | 2-6,1-6 | |
| ITF W25 - Haag | 06/30 10:00 | 25 | [485] Tatiana Pieri v Valentini Grammatikopoulou [278] | 2-6,1-6 | |
| ITF W60 - Stare Splavy | 06/15 09:40 | 54 | [278] Valentini Grammatikopoulou v Andreea Prisacariu [483] | 5-7,4-6 | |
| ITF W60 - Stare Splavy | 06/14 12:25 | 54 | Valentini Grammatikopoulou v Laetitia Pulchartova | 4-6,6-2,10-7 | |
| ITF W25 - Montemor-O-Novo | 06/11 09:00 | 27 | [287] Valentini Grammatikopoulou v Beatriz Haddad Maia [225] | 1-6,5-7 |