Eileen Demes (born 13 October 1997) is a German track and field athlete who competes in the 400m hurdles.

[4] Demes won the German U23 title over 400m hurdles in 2018, but her athletic progress was halted by a viral infection that was not initially accurately diagnosed, and from which recovery was not quick.

[5] Demes finished second in the 400m hurdles at the German national championships in Kassel in July 2023, with a personal best time of 55.72.

[7] Selected for the 2023 World Athletics Championships in Budapest in August 2023, she qualified for the semi-final in a personal best time of 55.29.

[8] She was selected for the 2024 European Athletics Championships in Rome, reaching the semifinals and running a personal best 55.29 seconds.