Klaus Sonnleitner was born in Bad Ischl in 1970. He received his musical education at the University of Music and Dramatic Arts Mozarteum in Salzburg. There he studied organ with Elisabeth Ullmann with a focus on Catholic Church Music as well as Instrumental Pedagogy. In 1995 he graduated with honours and received an award from the Austrian Federal Ministry of Science and Art. From 1990 to 1995 he taught organ and piano at various music schools. He actively participated not only in a considerable number of master classes, but also in competitions with a focus on the interpretation of Early Music. In 1995 he began his studies in Theology in Linz.
In 1997 he became a member of the Augustinian Canons at the monastery of St. Florian. He graduated from the Private Catholic University of Linz in 2001 and became an ordained priest the following year, focusing on pastoral work until 2006. Since this time Klaus Sonnleitner has been the collegiate organist at the monastery of St. Florian, chaplain in various parishes, as well as guest master at the monastery. He continues to perform in concert and as a recording artist, and is an organ adviser and editor of the organ music of his predecessors Franz Xaver Möller and Augustinus Franz Kropfreiter. From 2011 to 2015 he was on the jury at the International Organ Competition in St-Maurice/Valais (Switzerland) and in September 2013 he was invited to play at the BBC Proms at the Royal Albert Hall in London as successor of Anton Bruckner as abbey organist of St. Florian.