Born in 1985 in Siegburg. Benjamin Lillie gained his first theatre experience in 2004 with projects at Theater Bonn (Reality Bites) and the Bayer Kultur Erholungshaus in Leverkusen. From 2008 to 2012, he studied acting at the Felix Mendelssohn Bartholdy University of Music and Theatre in Leipzig. In the 2012/13 season, he was a member of the ensemble at Schauspiel Leipzig. From 2013/14 to the 2018/19 season, he was a member of the ensemble at Deutsches Theater Berlin. Here he worked with directors such as Christopher Rüping, René Pollesch, Karin Henkel, Stefan Pucher, Jette Steckel, Sebastian Hartmann, Stefan Kimmig and Bastian Kraft. He received the Grimme Prize in 2017 for his performance in the feature film Dead Man Working. Benjamin Lillie was a permanent member of the ensemble at Schauspielhaus Zürich from the 2019/20 season. In 2021, he was named Actor of the Year in the 'theater heute' critics' poll. 

Since the 2024/25 season, he has been a member of the ensemble at Deutsches Theater.