| ITF W35 Klagenfurt | 05/30 07:50 | 27 | Wakana Sonobe v Sofia Costoulas | 4-6,6-7 | |
| ITF W35 Klagenfurt | 05/29 09:10 | 26 | [212] Oana Gavrila v Sofia Costoulas [341] | 0-6,2-6 | |
| ITF W35 Klagenfurt | 05/28 07:30 | 25 | [404] Elena Malygina v Sofia Costoulas [341] | 3-6,6-3,4-6 | |
| ITF W35 Annenheim | 05/24 10:35 | 28 | [281] Sofia Costoulas v Tereza Valentova [334] | 5-7,1-6 | |
| ITF W35 Annenheim | 05/23 16:00 | 27 | [281] Sofia Costoulas v Nika Radisic [378] | 6-2,6-3 | |
| ITF W35 Annenheim | 05/22 15:30 | 26 | [281] Sofia Costoulas v Mara Guth [501] | 2-6,6-1,6-3 | |
| ITF W35 Annenheim | 05/22 07:00 | 25 | Sofia Costoulas v Mila Masic | 6-2,6-2 | |
| ITF W35 Bastad | 05/09 08:10 | 26 | [457] Irina Fetecau v Sofia Costoulas [291] | Retired | |
| ITF W35 Bastad | 05/07 11:25 | 25 | Maileen Nuudi v Sofia Costoulas | 2-6,6-7 | |
| Billie Jean King Cup | 04/13 19:05 | 64 | Emma Navarro v Sofia Costoulas | Cancelled | |
| Billie Jean King Cup | 04/12 22:00 | 64 | [5] Jessica Pegula v Sofia Costoulas [279] | 4-6,6-2,6-3 | |
| ITF W50 Kashiwa | 04/05 03:15 | 27 | [356] Ya-Hsuan Lee v Sofia Costoulas [285] | 6-1,6-2 | |
| ITF W50 Kashiwa | 04/04 03:30 | 26 | [285] Sofia Costoulas v Priscilla Hon [189] | 6-2,6-2 | |
| ITF W50 Kashiwa | 04/02 03:40 | 25 | [285] Sofia Costoulas v Sohyun Park [299] | 6-2,6-2 | |
| ITF W50 Kofu | 03/28 03:10 | 26 | [286] Sofia Costoulas v Destanee Aiava [196] | 3-6,4-6 | |
| ITF W50 Kofu | 03/27 04:00 | 25 | Sofia Costoulas v Rin Nakagawara | 6-1,6-2 | |
| ITF W15 Hinode | 03/23 01:00 | 28 | Sofia Costoulas v Maegan Manasse | 2-6,3-6 | |
| ITF W15 Hinode | 03/22 00:55 | 27 | Sofia Costoulas v Dabin Kim | 3-6,6-3,6-0 | |
| ITF W15 Hinode | 03/21 04:20 | 26 | Sofia Costoulas v Kisa Yoshioka | 6-0,6-3 | |
| ITF W15 Hinode | 03/20 05:00 | 25 | Sofia Costoulas v Yui Chikaraishi | 6-0,6-2 | |
| ITF W35 Santo Domingo | 03/13 13:25 | 25 | [279] Sofia Costoulas v Maria F H Gonzalez [205] | 6-0,3-6,3-6 | |
| ITF W35 Santo Domingo | 03/08 15:15 | 27 | [226] Elvina Kalieva v Sofia Costoulas [279] | 6-7,6-4,6-0 | |
| ITF W35 Santo Domingo | 03/07 16:15 | 26 | [278] Varvara Lepchenko v Sofia Costoulas [279] | 6-7,4-6 | |
| ITF W35 Santo Domingo | 03/06 15:05 | 25 | [471] Maria Sara Popa v Sofia Costoulas [279] | 2-6,5-7 | |
| ITF W50 Pretoria | 02/27 10:05 | 25 | [296] Jaeda Daniel v Sofia Costoulas [274] | 7-5,6-2 | |
| ITF W50 Pretoria | 02/20 13:00 | 25 | [377] Kaylah McPhee v Sofia Costoulas [274] | 6-3,6-2 | |
| ITF W50 Roehampton | 02/15 13:35 | 26 | [278] Nikola Bartunkova v Sofia Costoulas [276] | 6-3,6-1 | |
| ITF W50 Roehampton | 02/14 09:55 | 25 | [493] Johanne C Svendsen v Sofia Costoulas [276] | 4-6,3-6 | |
| ITF W75 Rome (GA) | 01/31 18:20 | 25 | [258] Sofia Costoulas v Valeriya Strakhova [242] | 3-6,7-5,4-6 | |
| ITF W75 Vero Beach | 01/23 20:05 | 25 | [248] Sofia Costoulas v Sachia Vickery [137] | 6-2,3-6,2-6 |
Sofia Costoulas (Genk, 2 aprile 2005) è una tennista belga.