Lena Ostermeier (born 1 October 1996) is a German footballer who plays as a midfielder for SGS Essen.^[1][2][3][4]

Ostermeier started playing football in Dortmund with the Sportfreunde Sölderholz in 1893 and went through several youth departments.

In the summer of 2012 she moved from the B-juniors at SF Sölderholz 1893 to SGS Essen in the youth department and played with the B-juniors in the newly founded Bundesliga West/Southwest.^[5][6] Due to a reduced squad due to injury, Ostermeier was promoted from the U-17 to the Bundesliga squad at the beginning of 2013.^[7]

On March 31, 2013, at the age of 16, she made her Bundesliga debut in the away game at VfL Wolfsburg when she came on as a substitute for Linda Dallmann in the 89th minute of the game.^[8]

In the 2023–24 season, she scored the winner in the 1-0 away victory against 1. FC Köln.^[9]

Ostermeier has a Dr. rer. nat. on the topic “Stability of selected liquid-liquid phase separations in biomolecular systems” from 2023. She wrote this at the TU Dortmund in the Faculty of Chemistry and Chemical Biology in the Department of Physical Chemistry with Prof. (ret.) Roland Winter.^[10]