Alexej Lochmann, born in Qaraghandy in present-day Kazakhstan, studied at the University of Music and Performing Arts in Frankfurt am Main.

He was a member of the acting studio at Schauspiel Frankfurt in the 2015/16 season. Lochmann was awarded the Critics' Prize at the Radikal Jung festival for his production of Fräulein Julie. From the 2016 to 2020 season, Alexej Lochmann was a member of the Düsseldorf Schauspielhaus ensemble. He has been a permanent member of the Schauspielhaus Graz since 2020.

Alexej Lochmann has been a member of the ensemble at Deutsches Theater Berlin since the 2023/24 season.