(Chaim) Herman Müntz (28 August 1884, in Łódź – 17 April 1956, in Sweden) was a German mathematician, now remembered for the Müntz approximation theorem.
He was born in Łódź (then in the Piotrków Governorate of the Russian Empire, now in Poland) in a secular Jewish family, who had adopted a German spelling of the surname Minc. He was educated there and at the Friedrich-Wilhelms-Universität in Berlin, graduating in 1906. He wrote a doctoral dissertation there on partial differential equations and the Plateau problem, in 1910, supervised by H. A. Schwarz.
In 1911 he moved to Munich. In the following years he published on projective geometry, iterative methods, and approximation theory.
In 1914 he took a teaching position in a school near Heppenheim, and a year later another in Hochwaldhausen. He became a German citizen in 1919. At around that time he suffered a breakdown, and moved back to Poland with his wife. He shortly began publishing mathematics again. The couple moved to Göttingen in 1921, and Müntz became involved in editorial, reviewing and translation work, as well as research. At this period, and from 1924 in Berlin, he was unsuccessfully trying to get an academic position, hampered because he had not habilitated. In 1927 he worked closely with Albert Einstein.