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 25 June 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.