Martin Benno Schmidt (23 August 1863 – 27 November 1949) was a German pathologist born in Leipzig.
He spent several years as an assistant at the University of Strasbourg, where he worked under Friedrich Daniel von Recklinghausen (1833-1910).
In 1906 he became a professor of pathology at the medical academy in Düsseldorf, and afterwards worked as a pathologist in Zurich and Marburg.
In 1913 he succeeded Richard Kretz (1865-1920) as professor of pathology at the University of Würzburg, a position he maintained until his retirement in 1934.
Schmidt specialized in pathological investigations of bone disorders such as rickets, osteogenesis imperfecta, and osteomalacia.
He is remembered for his description of autoimmune polyendocrine syndrome, type II, a disease characterized by autoimmune activity against more than one endocrine gland.
This condition is sometimes referred to as "Schmidt's syndrome".
He also performed important studies involving iron metabolism.