Hardt is a German surname. Notable people with the surname include:
Dick Hardt (born 1963), American-Canadian software executive Ernst Hardt (1876–1947), German author Heinz Hardt (1936-2025), German politician Jürgen Hardt (born 1963), German politician Karin Hardt (1910-1992), German actress Michael Hardt (born 1960), American philosopher Mickey Hardt (born 1969), German actor Nick Hardt (born 2000), Dominican tennis player