Carl Christian Clemen (30 March 1865, near Leipzig – 8 July 1940, Bonn), best known as Carl Clemen, was a German theologian and religious historian. He was a member of the history of religions school.

Clemen was Professor of New Testament and religious history at the University of Bonn. He was a critic of the Christ myth theory and refuted the arguments of Arthur Drews, Peter Jensen and other mythicists. He was also critical of the ideas of Anthroposophy and Theosophy.

Clemen has approximately six hundred publications. His brothers were art historian Paul Clemen and historian Otto Clemen.