Born into a musical family, at five-years-old Stefan Geiger began playing piano, violin, drums and trombone. Following his studies supported by the German Academic Foundation Studienstiftung des deutschen Volkes he won several international competitions (1989 at the Concours International du Festival du Musique du Toulon; 1992 at the competition of the “Prague Spring” festival) and became a solo trombonist at Munich’s Bayerische Staatsoper. He later held the same position at NDR Elbphilharmonie Orchester in Hamburg.
Following his conducting studies, he was assistant to Christoph Eschenbach, Valery Gergiev and Christoph von Dohnanyi. He soon became Artistic Director of the Landesjugendorchester Bremen and conducted from 2002 -2007 the HFK Orchestra of Bremen (Hochschule für Künste Bremen) as part of a guest professorship.
Geiger has conducted numerous orchestras including the NDR Elbphilharmonie Orchester, NDR Radiophilharmonie, Deutsche Kammerphilharmonie Bremen, Sinfonieorchester des Hessischen Rundfunks, Schleswig-Holstein Festival Orchester, Ensemble Resonanz, Würzburger Philharmoniker, Nürnberger Symphoniker, Württembergische Philharmonie Reutlingen, Wuppertaler Sinfonieorchester, Norddeutsche Philharmonie Rostock, Dortmunder Philharmoniker, Royal Scottish National Orchestra, Royal Northern Sinfonia, Orchestra Sinfonica di Milano, Oulu Symphony Orchestra, Lahti Symphony Orchestra, Romanian Radio Orchestra, Orquestra Sinfônica Brasileira, Orquestra Sinfônica de Porto Allegre, Orquestra Sinfônica de Bahia, Orquestra Sinfônica de Sao Paulo at Sala Sao Paulo and Buenos Aires Philharmonic Orchestra at the Teatro Colon in Argentina.
Stefan Geiger is co-founder and jury chairman of the "German Games Music Award", a competition in cooperation with Radio Bremen, which provides a forum for young composers who write sophisticated music for computer games. This idea not only found a large audience on the Internet - the Internet stream of the first event in 2012 became one of the most clicked contributions of its kind on "ARTE Concert" - but is successfully continued to this day and led to his expertise in the field of game music. Furthermore, he is a sought-after conductor for "live to screen" film music accompaniments.