Stefan Bäumler started singing at vocational college for music in Sulzbach-Rosenberg, Bavaria, as a student of Jürgen Nennemann from 2001 to 2003. After, he began to study at University of Music Saarbrücken and became a student of Prof. Renate Stoll and Berthold Hirschfeld. He finished with a degree in 2008. Till today he still is a private student in Hamburg and is working as a freelancer.

He gained stage experience at several productions, where he was singing for example in The turn of the screw, La finta semplice and Alcina. He also was involved with Willy Decker's new production of Moses and Aron at Ruhrtriennale in 2009.

Furthermore, he acquired a wide repertory of sacred music and is performing as a singer in sacred concerts and oratorios. Performances of lieder recitals are an extensive part of his repertoire.

Masterclasses and projects at Schleswig-Holstein Musik Festival as well as with Rolando Villazón, Helmuth Rilling, Stefan Parkman, Christopher Hogwood, Paul McCreesh, Sir Roger Norrington,Rolf Beck, Rupert Huber and Bobby McFerrin have enriched his artistic work.

There are sound and video recordings at NDR, SR, SWR, WDR and ARTE.