Hans Lietzmann (2 March 1875 – 25 June 1942) was a German Protestant theologian and church historian who was a native of Düsseldorf.
He initially studied in Jena, then continued his education in Bonn, where he was a student of Hermann Usener (1834–1905). In 1905 he was appointed professor of church history at the University of Jena, and in 1923 was a successor to Adolf von Harnack (1851–1930) at the University of Berlin. During his career he obtained an honorary doctorate from the University of Athens, and in 1927 became a member of the Prussian Academy of Sciences. He died in Locarno, Switzerland on June 25, 1942.
Largely known for his work as a church historian and for his research of the New Testament, Lietzmann was also an authority in the fields of archaeology, classical philology and papyrology.
Lietzmann was the author of the four volume Geschichte der Alten Kirche (History of the Early Church) and Messe und Herrenmahl (Mass and Lord’s Supper); both works later being translated and published in English. Other significant books by Lietzmann include: