Friedhelm Marx was born in Greven, Westphalia, in 1963. He studied German and Catholic theology at the University of Tübingen and the University of Virginia. He then moved to the Rheinische Friedrich-Wilhelms-Universität Bonn, where he completed his studies.

He subsequently worked as a research assistant in the Department of Linguistics and Literature at the University of Wuppertal for several years. In 1994, he gained his doctorate in German Philology at the University of Bonn with a thesis on novels by Johann Wolfgang von Goethe and Martin Wieland. His subsequent habilitation focused on the depiction of Christ in the works of Thomas Mann.

He was appointed Max Kade Distinguished Visiting Professor at the University of Notre Dame in South Bend, USA. In 2004, he took over the Chair of Modern German Literature at the University of Bamberg. There, he also became Vice Dean, Dean, and a member of the Senate and the University Council, sometimes acting as Chairman.

Friedhelm Marx serves as a liaison lecturer at the Konrad Adenauer Foundation and the Max Weber Foundation of Bavaria. He is also a member of the International Advisory Board of Jahrbuch für Gegenwartsliteratur and has been Vice-President of the German Thomas Mann Society since 2006. He has served as a juror on various literary awards panels, including those for the E.T.A. Hoffmann Prize, the Bavarian State Prize for the Promotion of the Arts (Literature), the Thomas Mann Literature Prize of the City of Lübeck and the Bavarian Academy of Fine Arts, and the Jean Paul Literature Prize. He is currently a juror for the 2025 Deutscher Buchpreis (German Book Prize).

He is Chairman of the Bamberg Theatre Association and has been a corresponding member of the Bavarian Academy of Fine Arts since 2020. In 2021, he spent several months as a Thomas Mann Fellow at the Thomas Mann House in Pacific Palisades, Los Angeles.