Grothaus, Grothus, or Grotthuss is a surname. Notable people with the surname include:
Eleonore von Grothaus (1734–1794), German noblewoman, writer, poet, lay musician, educator Gisela Grothaus (born in Berlin), West German slalom canoeist Michael Grothaus (born 1977), American novelist and journalist Edward Bernard Grothus (1923-2009), American anti-nuclear activist Theodor Grotthuss (1785-1822), German chemist