Sofia Costoulas (; born 2 April 2005) is a Belgian professional tennis player. She has career-high rankings of No. 134 in singles, achieved on 30 March 2026, and No. 229 in doubles, reached on 25 September 2023.

Early life Costoulas was born in Genk, Belgium to a Greek-Congolese father and a Belgian mother. Her father Sotiris was a professional footballer who played for Sint-Truidense V.V., K. Patro Eisden Maasmechelen, and C.S. Visé. She began playing tennis at the age of four. She trained at her local club in Genk, the Kim Clijsters Academy, and the Justine Henin Academy.

Career overview Juniors In July 2021, she and Laura Hietaranta reached the girls' doubles final of Wimbledon, but lost to Kristina Dmitruk and Diana Shnaider. In September 2021, she reached the girls' singles third round of the US Open.

In January 2022, Costoulas won the J1 Traralgon Tennis International, defeating Kayla Cross in the final. Later that month, she reached the girls' singles final of the Australian Open, but lost to Petra Marčinko. In April 2022, she won back-to-back J1 titles in Vrsar and Plovdiv. The following month, she also won the JA International HTV Junior Open in Offenbach am Main.

Professional In December 2021, Costoulas reached back-to-back W15 finals in Monastir. In February 2022, she reached the semifinals of the W25 Copa Banco in Guayaquil. In October 2022, she won her first professional doubles title at the W25 tournament in Hua Hin, partnering Punnin Kovapitukted.

In April 2025, she won her biggest title to-date at the W75 Ladies Open Calvi Eaux de Zilia, defeating Tessah Andrianjafitrimo in the final. The following month, she reached the second round of the qualifying competition of the French Open, but ultimately failed to advance into the main draw.

Costoulas made her WTA Tour main-draw debut as a qualifier at the 2026 Auckland Open and defeated fellow qualifiers Whitney Osuigwe and Kaitlin Quevedo to reach the quarterfinals, at which point her run was ended by third seed Iva Jovic.

Playing alongside Matilde Jorge, Costoulas won her first WTA 125 doubles title at the 2026 Oeiras Open, defeating Magali Kempen and Lara Salden in the final.

Grand Slam performance timeline

Singles Tournament20252026W–L Australian OpenAQ10–0 French OpenQ2Q30–0 WimbledonQ1Q10–0 US OpenQ1Q20–0Win–loss0–00–00–0

WTA 125 finals

Doubles: 1 (title) ResultW–LDateTournamentSurfacePartnerOpponentsScoreWin1-0Oeiras CETO Open, PortugalClay Matilde Jorge Magali Kempen Lara Salden6–4, 6–2

ITF Circuit finals

Singles: 13 (5 titles, 8 runner-ups) LegendW75 tournamentsW50 tournamentsW25/35 tournamentsW15 tournamentsFinals by surfaceHard (4–6)Clay (1–2)

ResultW–LDateTournamentTierSurfaceOpponentScoreLoss 0–1 Feb 2021ITF Sharm El Sheikh, EgyptW15 Hard Magali Kempen 3–6, 2–6Loss 0–2 Dec 2021ITF Monastir, TunisiaW15 Hard Eudice Chong 6–3, 4–6, 6–7(5)Loss 0–3 Jan 2022ITF Monastir, TunisiaW15 Hard Akvilė Paražinskaitė 5–7, 2–6Loss 0–4 Jun 2022ITF Gurugram, IndiaW25 Hard Karman Thandi 4–6, 6–2, 1–6Win 1–4 May 2023ITF Feld am See, AustriaW25 Clay Lara Salden 6–3, 6–1Loss 1–5 Nov 2023ITF Limassol, CyprusW25 Hard Hanne Vandewinkel 2–6, 6–4, 4–6 Win 2–5 Dec 2023ITF Limassol, CyprusW25 Hard Silvia Ambrosio 6–1, 6–3Loss 2–6 May 2024ITF Klagenfurt, AustriaW35 Clay Marie Benoît 1–6, 3–6Win 3–6 Mar 2025ITF Helsinki, FinlandW35 Hard (i) Lily Miyazaki 6–3, 7–5Win 4–6 Apr 2025ITF Calvi, FranceW75 Hard Tessah Andrianjafitrimo 7–5, 6–1Loss 4–7 May 2025ITF Otočec, SloveniaW50 Clay Amarissa Tóth 3–6, 3–6Loss 4–8 Aug 2025ITF Heraklion, GreeceW35 Hard Lola Radivojević 0–6, 1–4 ret.Win 5–8 Mar 2026Kōfu International Open, JapanW75 Hard Ma Yexin 7–5, 6–3

Doubles: 12 (4 titles, 8 runner-ups) LegendW60/75 tournamentsW50 tournamentsW25/35 tournamentsW15 tournamentsFinals by surfaceHard (2–6)Clay (2–1)Carpet (0–1)

ResultW–LDateTournamentTierSurfacePartnerOpponentsScoreLoss 1–0 Feb 2022ITF Monastir, TunisiaW15 Hard Clervie Ngounoue Kristina Dmitruk Maria Sholokhova 6–3, 2–6, [5–10]Win 1–1 Oct 2022ITF Hua Hin, ThailandW25 Hard Punnin Kovapitukted Risa Ushijima Wi Hwi-won 6–1, 6–2Loss 1–2 Mar 2023ITF Pretoria, South AfricaW60 Hard Dalila Spiteri Mai Hontama Alice Tubello 3–6, 3–6Loss 1–3 May 2023ITF Feld am See, AustriaW25 Clay Kayla Cross Denisa Hindová Chiara Scholl 2–6, 0–6Win 2–3 Jun 2023ITF Troisdorf, GermanyW25 Clay Lara Salden Chiara Scholl Tilwith Di Girolami 7–6(4), 6–4Win 3–3 Jun 2023ITF Tainan, TaiwanW25 Clay Li Yu-yun Lee Ya-hsin Lee Ya-hsuan 6–4, 6–4Loss 3–4 Jul 2023ITF Corroios, PortugalW25 Hard Lulu Sun Talia Gibson Petra Hule 3–6, 6–3, [6–10]Loss 3–5 Sep 2023ITF Leiria, PortugalW25 Hard Jenny Dürst Francisca Jorge Matilde Jorge 5–7, 6–7(5)Loss 3–6 Feb 2024ITF Pretoria, South Africa W50 Hard Hanne Vandewinkel Lina Glushko Gabriela Knutson 6–7(5), 6–7(4)Loss 3–7 Mar 2025ITF Solarino, Italy W35 Carpet Katharina Hobgarski Viktória Hrunčáková Katarína Kužmová 7–6(4), 4–6, [5–10]Loss 3–8 Mar 2025Open Nantes Atlantique, FranceW50 Hard (i) Talia Gibson Martyna Kubka Lisa Zaar 3–6, 2–6Win 4–8 Mar 2026All Japan Indoor ChampionshipsW75 Hard (i) Sofya Lansere Hayu Kinoshita Sara Saito 6–2, 6–4

Junior Grand Slam tournament finals

Singles: 1 (runner-up) ResultYearTournamentSurfaceOpponentScoreLoss2022Australian OpenHard Petra Marčinko5–7, 1–6

Doubles: 1 (runner-up) ResultYearTournamentSurfacePartnerOpponentsScoreLoss2021WimbledonGrass Laura Hietaranta Kristina Dmitruk Diana Shnaider1–6, 2–6

Notes

References

External links