Jun Keller was born in 1973 in Stuttgart and began his violin studies a the age of six with Prof. Petru Munteanu in Lübeck. In 1987 he continued his studies at the Vienna Music Academy under Prof. Gerhart Hetzel until the latter's tragic death in 1992. He completed his diploma in Vienna one year later. He participated in numerous master classes with Zakhar Bron, Dorothy DeLay, Ivry Gitlis, Igor Oistrach, Igor Ozim and Dénes Zsigmondy as well intensively pursuing his interest in chamber music under the tutelage of Franz Bayer, the Bartok Quartet, Thomas Kakuska (Alban Berg Quartet), Peter Matzka (Vienna String Sextet), Johannes Meissl (Artis Quartet) and Christoph Poppen (Cherubibni Quartet). In 1995 he completed his studies at the Academy of Music Hanns Eisler in Berlin with the highest distinction. After one year as a member of the Munich Chamber Orchestra, he began his tenure in the Vienna State Opera Orchestra and advanced in 2002 to the Vienna Philharmonic as section leader of the first violins.
Since 1985 Jun Keller has performed as a soloist and chamber musician in Austria and abroad. In 1990 on the occasion of the TV Gala of the Austian Jeunesses Musicales he received first prize after having won the German national competition "Jugend musiziert" in 1986. In 1992 he became a member of the Hugo Wolf String Quartet, was for four years member of the Ensemble Vienna Concertino as well as the Wiener Virtuosen and the Steude Quartet until 2004.