| ITF W25 Limassol | 12/03 09:00 | 29 | [255] 암브로시오, 실비아 v Costoulas, Sofia [296] | 1-6,3-6 | |
| ITF W25 Limassol | 12/02 08:00 | 28 | [296] Costoulas, Sofia v 자카로바, 아나스타시아 [192] | 7-6,7-5 | |
| ITF W25 Limassol | 12/01 08:00 | 27 | [296] Costoulas, Sofia v Polina Iatcenko [358] | 7-5,7-5 | |
| ITF W25 Limassol | 11/30 08:00 | 26 | [296] Costoulas, Sofia v Hanne Vandewinkel [343] | 7-5,6-1 | |
| ITF W25 Limassol | 11/29 08:00 | 25 | Costoulas, Sofia v 윌게스, 안젤리나 | 3-6,7-6,6-0 | |
| ITF W25 Limassol | 11/26 09:00 | 29 | [330] Hanne Vandewinkel v Costoulas, Sofia [291] | 6-2,4-6,6-4 | |
| ITF W25 Limassol | 11/25 08:00 | 28 | [291] Costoulas, Sofia v 자카로바, 아나스타시아 [192] | 6-2,7-5 | |
| ITF W25 Limassol | 11/24 12:10 | 27 | Costoulas, Sofia v Rebecca Munk Mortensen | 6-3,6-2 | |
| ITF W25 Limassol | 11/23 08:00 | 26 | [291] Costoulas, Sofia v Polina Iatcenko [356] | 6-4,6-0 | |
| ITF W25 Limassol | 11/22 08:00 | 25 | [291] Costoulas, Sofia v 칼코우스카, 웨로니카 [333] | 6-3,6-2 | |
| ITF W40 Petange | 11/17 16:00 | 27 | [101] 도딘, 오션 v Costoulas, Sofia [297] | 6-2,7-5 | |
| ITF W40 Petange | 11/16 08:50 | 26 | Costoulas, Sofia v Veronika Podrez | 6-3,3-6,6-1 | |
| ITF W40 Petange | 11/15 12:55 | 25 | [267] 루직, 안토니아 v Costoulas, Sofia [297] | 4-6,7-6,1-6 | |
| ITF W60 Nantes | 10/30 16:05 | 25 | [297] Costoulas, Sofia v 코스틱, 나탈리야 [185] | 2-6,7-6,4-6 | |
| ITF W80 Poitiers | 10/26 12:20 | 26 | [111] 프리에드삼, 안나-레나 v Costoulas, Sofia [296] | 6-3,6-2 | |
| ITF W80 Poitiers | 10/24 08:30 | 25 | 조스타크, 마린 v Costoulas, Sofia | 1-6,7-6,2-6 | |
| ITF W60 Hamburg | 10/17 09:10 | 25 | Alevtina Ibragimova v Costoulas, Sofia | 2-6,6-4,6-4 | |
| ITF W40 Quinta do Lago | 10/11 09:00 | 25 | [131] Gadecki, Olivia v Costoulas, Sofia [281] | 7-6,6-1 | |
| ITF W25 Santarem | 09/27 13:15 | 25 | 포고시, 라우라 v Costoulas, Sofia | Cancelled | |
| ITF W25 Santarem | 09/27 09:00 | 25 | 차라에바, 알리나 v Costoulas, Sofia | 6-2,3-6,6-4 | |
| ITF W25 Ceuta | 09/23 12:05 | 28 | [291] Costoulas, Sofia v 팔레이, 알리오나 [340] | 6-3,4-6,0-6 | |
| ITF W25 Ceuta | 09/22 09:30 | 27 | Pavlova, Kira v Costoulas, Sofia | 5-7,3-6 | |
| ITF W25 Ceuta | 09/21 08:00 | 26 | Anastasiia Grechkina v Costoulas, Sofia | 4-6,2-6 | |
| ITF W25 Ceuta | 09/19 13:30 | 25 | 루시티, 알린다 v Costoulas, Sofia | 4-6,6-1,2-6 | |
| ITF W25 Leiria | 09/14 10:00 | 26 | [288] Costoulas, Sofia v 구에레로 알바레즈, 에바 [434] | 4-6,6-3,3-6 | |
| ITF W25 Leiria | 09/13 13:15 | 25 | Costoulas, Sofia v Ranah Akua Stoiber | 6-3,6-0 | |
| ITF W25 Verbier | 08/23 08:55 | 25 | [299] Costoulas, Sofia v Bonardi, Berta [419] | 7-5,5-7,3-6 | |
| ITF W25 Bistrita | 08/18 11:20 | 27 | [299] Costoulas, Sofia v 아마리에이, 일린카 달리나 [438] | 6-7,3-6 | |
| ITF W25 Bistrita | 08/17 13:05 | 26 | Costoulas, Sofia v 피에리, 제시카 | 7-6,6-4 | |
| ITF W25 Bistrita | 08/15 12:15 | 25 | Costoulas, Sofia v Szabo, Briana | 6-3,6-1 |
Sofia Costoulas (born 2 April 2005) is a Belgian tennis player.
Costoulas has a Greek–Congolese father and a Belgian mother.
Costoulas has a career-high singles ranking by the Women's Tennis Association (WTA) of 248 and a best doubles ranking of 229.
On the ITF Junior Circuit, she had a career-high combined ranking of No. 2, achieved on 18 April 2022. She lost the girls' singles final of the 2022 Australian Open to Petra Marčinko. She had already reached the Wimbledon junior doubles final in 2021.