Karl Cardinal Lehmann (born May 16, 1936 in Sigmaringen) is a Cardinal of the Roman Catholic Church, Bishop of Mainz and chairman of the Congregation of the German Bishops (German: Deutsche Bischofskonferenz).

After school, Karl Lehmann studied philosophy and theology at the Albert Ludwigs Universität in Freiburg and the Collegium Germanicum et Hungaricum, a famous seminar for priests in Rome. He reached two academical degrees at the papal university Gregoriana. In 1968 he became professor at the Johannes-Gutenberg Universität in Mainz. From 1971 until 1983 he was professor at the Albert Ludwigs Universität in Freiburg.

He was elected Bishop in 1983 and confirmed by the Pope that same year. On 2 October 1983 he was consecrated by his predecessor Hermann Cardinal Volk in Mainz Cathedral.

In 1987, he became chairman of the Congregation of the German Bishops. He was reelected twice in 1993 and 1999. On 28 January 2001, Pope John Paul II appointed him cardinal.