Andreas Kohn studied singing at the Mozarteum in Salzburg with Karl Christian John and made his début as an ensemble singer at the opera studio of the Bavarian State Opera and at the Hessisches State Theatre. He is a laureate of numerous competitions including the Mozart international competition of Würzburg and the VDMK competition of Berlin. After frequent appearances on the international stage in Geneva, Brussels and Salzburg among others, Andreas Kohn joined the ensemble of the Staatsoper Unter den Linden under the direction of Daniel Barenboim, where he performed such roles as the Minister in Fidelio, Basilio in The Barber of Seville, Kaspar in Le Freischütz and the king in Aïda. This led to an engagement with Daniel Barenboim for the Salzburg Festival, where Kohn sang Masetto in Don Juan directed by Patrice Chéreau.

After numerous appearances in Rome (in the roles of Fidelio and Parsifal), Venice (singing Fidelio at La Fenice), Barcelona, Athens, Geneva and Tokyo (in Elektra under the baton of Giuseppe Sinopoli), the United States (in the Seven Capital Sins with the Cleveland Orchestra directed by Christoph von Dohnányi), Andreas Kohn worked with Sir Georg Solti who engaged him for the 50th anniversary of the United Nations in Geneva (CD and DVD by Decca). In 2005, he accompanied the ensemble of the Bavarian State Opera in Tokyo where he appeared in The Mastersingers of Nuremberg under the baton of Zubin Mehta. Andreas Kohn has taught singing at the Bayerische Theaterakademie August Everding since 2004 and currently sings at the Bavarian State Opera notably in Carmen, Billy Budd, Moïse et Aaron, Salomé, Robert Devereux and The Magic Flute.