Potthast is a German surname. Notable people with the surname include:
August Potthast (1824–1898), German medieval historian and librarian Dan Potthast (born 1972), American guitarist, vocalist, songwriter Edward Henry Potthast (1857–1927), American impressionist painter Hedwig Potthast (1912–1994), German private secretary and mistress of Reichsführer-SS Heinrich Himmler