Hans Jantzen (April 26, 1881 in Hamburg – February 15, 1967 in Freiburg im Breisgau) was a German art historian specialized in Medieval art.
Jantzen first studied law, then history of art, archaeology and philosophy at various universities. For instance, at the University of Berlin he studied under Heinrich Wölfflin and at the University of Halle under Adolph Goldschmidt. In 1908 he completed his PhD dissertation on architecture depicted in Netherlandish paintings. In 1912, after finishing his Habilitationsschrift on color in Dutch painting of the 17th century, he taught art history in Halle.
In 1916, after a short period as a World War I soldier, he was appointed professor of art history at the University of Freiburg in the department Wilhelm Vöge had created. During his Freiburg years, he became a friend of Ernst Buschor, Ludwig Curtius, Edmund Husserl and Martin Heidegger. His attention turned to the Middle Ages, especially Gothic art. In 1925 he published a book on German sculptors of the thirteenth century and two years later his groundbreaking essay, "Über den gotischen Kirchenraum", which introduced the term, "diaphane Struktur" into discussions about Gothic architecture.
In 1931, he moved to the University of Frankfurt, and in 1935 he was appointed professor of art history at the Ludwig Maximilian University of Munich. As he sympathized with Nazi ideology for some time, he was dismissed from teaching after World War II, but reinstated shortly thereafter. In 1947 he published a monograph on Ottonian art. In 1951 he retired from Ludwig Maximilian University, returning to Freiburg where he lectured as an honorary professor in 1953. In 1962 he became known to English-speaking audiences when his book on three Gothic cathedrals, Kunst der Gotik, appeared in English as High Gothic.