Jan Andreesen is a German actor and voice actor born in Wilhelmshaven in 1980. He studied media studies at the University of Paderborn before completing his acting education from 2003 to 2007 at the Academy of Music and Theatre Felix Mendelssohn Bartholdy in Leipzig. Following his studies, Andreesen built a substantial career in German theatre, performing at venues including the Theater Bielefeld, Stadttheater Heidelberg, and as a long-standing ensemble member at the Staatstheater Karlsruhe from 2011 to 2016. His stage work encompassed a wide range of classical and modern roles in productions such as Dantons Tod, Die Leiden des jungen Werthers, and Drei Schwestern.

Alongside his stage career, Andreesen has been extensively active as a voice actor for film and television. He provided the German voice for the character Kouji Hiroo in the anime series Haikyu!! Land vs. Air, a role documented in the German Synchronkartei. His other voice work includes lending his voice to Shazad Latif in the series The Dark Crystal: Age of Resistance and voicing characters in the popular series Good Omens and The Rookie. Additionally, he voiced the character Masanori Shimizu in the anime series Shangri-La Frontier.

In addition to his voice acting, Andreesen has appeared in on-screen roles in German television productions, with appearances in series such as Die Rosenheim-Cops, SOKO Leipzig, and the television film Honigfrauen. He resides in Berlin.