# Sofia Costoulas

Sofia Costoulas (Greek: Κωστούλα, romanized: Kostoula; 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.

## Junior career
### Grand Slam performance

Singles:
* Australian Open: F (2022)
* French Open: 2R (2021)
* Wimbledon: 2R (2021)
* US Open: 3R (2021, 2022)
Doubles:
* Australian Open: QF (2020)
* French Open: SF (2022)
* Wimbledon: F (2021)
* US Open: 2R (2022)

## ITF Circuit finals
### Singles: 9 (3 titles, 6 runner-ups)

* Legend
* W25/35 tournaments
* W15 tournaments
* Finals by surface
* Hard (2–5)
* Clay (1–1)
| Result | W–L | Date | Tournament | Tier | Surface | Opponent | Score |
| Loss | 0–1 | Feb 2021 | ITF Sharm El Sheikh, Egypt | W15 | Hard | Magali Kempen | 3–6, 2–6 |
| Loss | 0–2 | Dec 2021 | ITF Monastir, Tunisia | W15 | Hard | Eudice Chong | 6–3, 4–6, 6–7$^{(5)}$ |
| Loss | 0–3 | Jan 2022 | ITF Monastir, Tunisia | W15 | Hard | Akvilė Paražinskaitė | 5–7, 2–6 |
| Loss | 0–4 | Jun 2022 | ITF Gurugram, India | W25 | Hard | Karman Thandi | 4–6, 6–2, 1–6 |
| Win | 1–4 | May 2023 | ITF Feld am See, Austria | W25 | Clay | Lara Salden | 6–3, 6–1 |
| Loss | 1–5 | Nov 2023 | ITF Limassol, Cyprus | W25 | Hard | Hanne Vandewinkel | 2–6, 6–4, 4–6 |
| Win | 2–5 | Dec 2023 | ITF Limassol, Cyprus | W25 | Hard | Silvia Ambrosio | 6–1, 6–3 |
| Loss | 2–6 | May 2024 | ITF Klagenfurt, Austria | W35 | Clay | Marie Benoît | 1–6, 3–6 |
| Win | 3–6 | Mar 2025 | ITF Helsinki, Finland | W35 | Hard (i) | Lily Miyazaki | 6–3, 7–5 |

### Doubles: 10 (3 titles, 7 runner-ups)

* Legend
* W60 tournaments
* W40/50 tournaments
* W25/35 tournaments
* W15 tournaments
* Finals by surface
* Hard (1–5)
* Clay (2–1)
* Carpet (0–1)
| Result | W–L | Date | Tournament | Tier | Surface | Partner | Opponents | Score |
| Loss | 1–0 | Feb 2022 | ITF Monastir, Tunisia | W15 | Hard | Clervie Ngounoue | Kristina Dmitruk Maria Sholokhova | 6–3, 2–6, [5–10] |
| Win | 1–1 | Oct 2022 | ITF Hua Hin, Thailand | W25 | Hard | Punnin Kovapitukted | Risa Ushijima Wi Hwi-won | 6–1, 6–2 |
| Loss | 1–2 | Mar 2023 | ITF Pretoria, South Africa | W60 | Hard | Dalila Spiteri | Mai Hontama Alice Tubello | 3–6, 3–6 |
| Loss | 1–3 | May 2023 | ITF Feld am See, Austria | W25 | Clay | Kayla Cross | Denisa Hindová Chiara Scholl | 2–6, 0–6 |
| Win | 2–3 | Jun 2023 | ITF Troisdorf, Germany | W25 | Clay | Lara Salden | Chiara Scholl Tilwith Di Girolami | 7–6$^{(4)}$, 6–4 |
| Win | 3–3 | Jun 2023 | ITF Tainan, Taiwan | W25 | Clay | Li Yu-yun | Lee Ya-hsin Lee Ya-hsuan | 6–4, 6–4 |
| Loss | 3–4 | Jul 2023 | ITF Corroios, Portugal | W25 | Hard | Lulu Sun | Talia Gibson Petra Hule | 3–6, 6–3, [6–10] |
| Loss | 3–5 | Sep 2023 | ITF Leiria, Portugal | W25 | Hard | Jenny Dürst | Francisca Jorge Matilde Jorge | 5–7, 6–7$^{(5)}$ |
| Loss | 3–6 | Feb 2024 | ITF Pretoria, South Africa | W50 | Hard | Hanne Vandewinkel | Lina Glushko Gabriela Knutson | 6–7$^{(5)}$, 6–7$^{(4)}$ |
| Loss | 3–7 | Mar 2025 | ITF Solarino, Italy | W35 | Carpet | Katharina Hobgarski | Viktória Hrunčáková Katarína Kužmová | 7–6$^{(4)}$, 4–6, [5–10] |

## Junior Grand Slam tournament finals
### Girls' singles: 1 (runner-up)

| Result | Year | Tournament | Surface | Opponent | Score |
| Loss | 2022 | Australian Open | Hard | Petra Marčinko | 5–7, 1–6 |

### Girls' doubles: 1 (runner-up)

| Result | Year | Tournament | Surface | Partner | Opponents | Score |
| Loss | 2021 | Wimbledon | Grass | Laura Hietaranta | Kristina Dmitruk Diana Shnaider | 1–6, 2–6 |