Larz Anderson (August 15, 1866 – April 13, 1937) was an American diplomat and bon vivant. He served as second secretary at the U.S. Legation to the Court of St. James's, London; as first secretary and later chargé d'affaires at the U.S. Embassy in Rome; as U.S. Minister to Belgium; and then briefly as the Ambassador to Japan. He also unsuccessfully sought appointment as Ambassador to Italy.