Thomas Schmitz received his first cello lessons at the age of nine, and already displaying a keen interest in chamber music before beginning his undergraduate studies, founded the Signum Quartet together with Annette Walther in 1994.

His studies in the class of Claus Kanngiesser at the Musikhochschule Köln were supplemented by a year of lessons with Dmitri Ferschtman in Amsterdam, as well as by the participation in various masterclasses with i.a. Wolfgang Boettcher (Berlin), Carter Brey (New York) and Arto Noras (Helsinki). In 1998 Thomas became a stipendiary of the Studienstiftung des deutschen Volkes.

After completing his diploma in Cologne, he was accepted into the Solistenklasse of Thomas Demenga at the Musikakademie in Basel, where he graduated in 2004 with the Solistendiplom. After a season with the Essener Philharmoniker, Thomas left the orchestra so as to dedicate himself solely to his work with the Signum Quartet.

Since 2005, Thomas has been a lecturer at the Hochschule für Musik Köln.