Mary Caldwell
Mary Caldwell may refer to:
 Mary Letitia Caldwell, American chemist
 Mary Gwendolin Caldwell, Marquise des Monstiers-Mérinville, American philanthropist and socialite
 Mary Tourtel, née Caldwell, British artist and creator of the comic strip Rupert Bear
 Mary Hay (actress), born Mary Hay Caldwell, American dancer and actress