Ecem Dönmez (born 29 October 1998) is a Turkish swimmer who specializes in freestyle swimming of 100 m and 200 m events.

[1] Dönmez competed in the 4 × 100 m freestyle relay event at the 2019 World Aquatics Championships in Gwangju, South Korea.

[2] She won the bronze medal together with Ela Naz Özdemir, Gizem Güvenç and Zehra Duru Bilgin in the 4 × 200 m freestyle relay event at the 2024 European Aquatics Championships in Belgrade, Serbia.

[3] She was qualified to represent her country at the 2024 Summer Olympics in Paris, France together with her teammates Ela Naz Özdemir, Gizem Güvenç and Zehra Bilgin within the first 16 teams with 8:05.21 in the Women's 4 × 200 m freestyle relay event of the 2024 World Aquatics Championships in Doha, Qatar.

[1][5] She studied Political science and International relations at Yeditepe University in Istanbul.