Oscar Cullmann (25 February 1902, Strasbourg - 16 January 1999, Chamonix) was a Christian theologian in the Lutheran tradition. He is best known for his work in the ecumenical movement, being in part responsible for the establishment of dialogue between the Lutheran and Roman Catholic traditions. Because of his intense ecumenical work, Cullmann's Basel colleague Karl Barth joked with him that his tombstone would bear the inscription "advisor to three popes." He was invited to be an observer at the Second Vatican Council.
Cullmann was born in Strasbourg (then in Germany) and studied classical philology and theology at the seminary there. In 1926 he accepted an assistant professorship, a position previously held by Albert Schweitzer.
In 1930 he was awarded a full professorship of New Testament, beginning in 1936 to also teach the history of the early church. In 1938, he began teaching both subjects at Basel Reformed Seminary. In 1948 he accepted a position teaching theology in Paris at the Sorbonne while he continued at Basel. He retired from both in 1972.
Cullmann's studies on Christian eschatology and Christology drove him to propose a third position over against the popular positions of C. H. Dodd and Albert Schweitzer, known as "redemptive history". He wrote that Jesus Christ was the midpoint of sacred history, which informs general history, and which runs linearly from creation to consummation. He stressed the objective reality of sacred history against the existentialist interpretation of Rudolf Bultmann, a fellow German theologian.
Upon his death at age 96, the World Council of Churches issued a special tribute to Cullmann in honor of his ecumenical work.