| Open de França - Feminino | 05/23 09:45 | 45 | [105] Heather Watson v Valentini Grammatikopoulou [193] | 5-7,7-6,6-7 | |
| Open de França - Feminino | 05/22 08:00 | 44 | [193] Valentini Grammatikopoulou v Kimberly Birrell [158] | 6-2,3-6,6-4 | |
| ITF - W60 La Bisbal | 05/15 14:40 | 25 | [120] Marie Bouzkova v Valentini Grammatikopoulou [196] | 6-3,6-2 | |
| ITF - W25 Óbidos | 05/11 13:30 | 28 | [198] Valentini Grammatikopoulou v Pemra Ozgen [252] | 3-6,4-6 | |
| ITF - W25 Óbidos | 05/11 09:00 | 27 | [198] Valentini Grammatikopoulou v Monika Kilnarova [324] | 6-0,4-6,6-4 | |
| ITF - W25 Óbidos | 05/10 13:00 | 26 | Valentini Grammatikopoulou v Lucie Wargnier | 6-4,3-6,6-3 | |
| ITF - W25 Óbidos | 05/08 13:00 | 25 | Valentini Grammatikopoulou v Anastasia Kulikova | 7-6,6-1 | |
| ITF - W60 Wiesbaden | 05/02 12:00 | 26 | [176] Katarina Zavatska v Valentini Grammatikopoulou [198] | 6-4,4-6,6-2 | |
| ITF - W60 Wiesbaden | 05/01 09:00 | 25 | [198] Valentini Grammatikopoulou v Julie Gervais [390] | 6-3,1-6,6-4 | |
| WTA - Estugarda | 04/20 09:30 | 45 | [195] Anna Zaja v Valentini Grammatikopoulou [199] | 7-6,7-6 | |
| ITF - W60 Istambul | 04/13 07:30 | 27 | [250] Jana Cepelova v Valentini Grammatikopoulou [178] | 7-5,6-4 | |
| ITF - W60 Istambul | 04/12 07:30 | 26 | [336] Berfu Cengiz v Valentini Grammatikopoulou [178] | 4-6,1-6 | |
| ITF - W60 Istambul | 04/09 11:30 | 25 | Polina Monova v Valentini Grammatikopoulou | Retired | |
| ITF - W25 Kofu | 03/20 07:30 | 25 | [453] Sandra Samir v Valentini Grammatikopoulou [174] | 1-6,7-5,7-6 | |
| ITF - W25 Nishi-Tama | 03/14 03:50 | 26 | [171] Valentini Gram'lou v Jodie Anna Burrage [345] | 2-6,4-6 | |
| ITF - W25 Nishi-Tama | 03/13 02:25 | 25 | [171] Valentini Gram'lou v Catherine Harrison [472] | 7-5,2-6,7-6 | |
| ITF - W60 Shrewsbury | 02/12 18:10 | 25 | [369] Jodie Anna Burrage v Valentini Grammatikopoulou [171] | Retired | |
| 2019 Fed Cup | 02/09 12:00 | 28 | [171] Valentini Grammatikopoulou v Berfu Cengiz [331] | Retired | |
| 2019 Fed Cup | 02/08 16:30 | - | [171] Valentini Grammatikopoulou v Kaja Juvan [169] | 7-6,5-7,6-3 | |
| 2019 Fed Cup | 02/07 16:30 | - | [83] Katie Boulter v Valentini Grammatikopoulou [171] | 6-3,4-6,6-3 | |
| 2019 Fed Cup | 02/06 16:30 | 1 | [311] Dalma Galfi v Valentini Grammatikopoulou [171] | 6-0,6-3 | |
| WTA - S. Petersburgo | 01/26 18:55 | 45 | [173] Valentini Grammatikopoulou v Jana Fett [218] | 1-6,1-6 | |
| Open da Austrália - Feminino | 01/10 06:55 | 45 | [107] Bianca Andreescu v Valentini Grammatikopoulou [173] | 6-4,6-1 | |
| Open da Austrália - Feminino | 01/09 05:05 | 44 | [173] Valentini Grammatikopoulou v Irina Bara [155] | 6-3,6-2 | |
| ITF - W25 Hong Kong | 01/04 03:45 | 27 | [172] Valentini Grammatikopoulou v Barbora Stefkova [300] | 5-7,3-6 | |
| ITF - W25 Hong Kong | 01/03 06:45 | 26 | [172] Valentini Grammatikopoulou v Hiroko Kuwata [269] | 6-4,0-6,7-6 | |
| ITF - W25 Hong Kong | 01/02 06:15 | 25 | Valentini Grammatikopoulou v Ho Ching Wu | 6-1,6-4 | |
| ITF - Dubai - Feminino | 12/10 09:40 | 25 | [104] Mandy Minella v Valentini Grammatikopoulou [172] | 6-1,6-4 | |
| WTA - Taipé da China | 11/15 09:30 | 26 | [160] Valentini Gram'lou v En Shuo Liang [276] | 3-6,1-6 | |
| WTA - Taipé da China | 11/14 03:00 | 25 | Kwan Yau Ng v Valentini Gram'lou | 2-6,2-6 |