Hanfstaengl (or Hanfstängl) is a German (Bavarian) surname, meaning "hemp stalk". Notable people with the surname include:
Franz Hanfstaengl (1804–1877), German painter, lithographer, and photographer; father of Edgar Edgar Hanfstaengl (1842–1910), son of Franz; art publisher and father of Erna and Ernst Marie Hanfstängl (1848–1917), German soprano Erna Hanfstaengl (1885–1981), daughter of Edgar, sister of Ernst, and confidant of Adolf Hitler and Unity Mitford Ernst Hanfstaengl (1887–1975), son of Edgar, brother of Erna, and confidant of Adolf Hitler and Franklin Delano Roosevelt Egon Hanfstaengl (1921–2007), son of Ernst, German-American art publisher