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 281 and a best doubles ranking of 253.
On the ITF Junior Circuit, she had a career-high combined ranking of No. 2, achieved on 18 April 2022. She lost the final of the 2022 Australian Open girls' singles 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: 5 (1 title, 4 runner-ups)
Doubles: 5 (2 titles, 3 runner-ups)
Junior Grand Slam tournament finals
Girls' singles: 1 (runner-up)
Girls' doubles: 1 (runner-up)