Cellist Clemens Hagen comes from a musical family in Salzburg and began to learn the cello at the age of six. Two years later he started to study at the Mozarteum University and then transferred to the Conservatory in Basle. Wilfried Tachezi and Heinrich Schiff were two of his teachers. In 1983 Clemens Hagen was awarded the special prize of the Vienna Philharmonic and also the Karl Böhm prize.

Clemens Hagen has performed as soloist with internationally renowned orchestras such as the Berlin Philharmonic, the Vienna Symphony, the Concertgebouw Orkest Amsterdam, the Camerata Salzburg, the Deutsche Kammerphilharmonie Bremen, the Chamber Orchestra of Europe, the NHK Orchestra Tokyo and the Cleveland Orchestra under conductors such as Claudio Abbado, Nikolaus Harnoncourt, Franz Welser-Möst, Sylvain Cambreling, Horst Stein, Ingo Metzmacher, Daniel Harding and Manfred Honeck.

For the 50th anniversary celebration of Jeunesse Musicale Vienna Clemens Hagen was artist-in-residence in the 1999/2000 season. He gave six concerts: performing as a duo with Oleg Maisenberg and Paul Gulda and also giving a solo recital of works by Bach. In addition he performed with the Toronto Symphony Orchestra under Jukka-Pekka Saraste as well as with the Hagen Quartet.

Clemens Hagen regards his appearances as soloist as an important complement to playing chamber music, primarily with the Hagen Quartet. Other chamber music partners are Martha Argerich, Evgeny Kissin, Mitsuko Uchida, Valery Afanassiev, Gidon Kremer, Leonidas Kavakos, Maxim Vengerov, Yuri Bachmet and Sabine Meyer.

Clemens Hagen is a professor at the Mozarteum University in Salzburg where he has taught cello and chamber music since 1988. He has also given master-classes in America and Japan.

Clemens Hagen plays a cello made by Antonius Stradivari dating from 1698.