William Cameron Forbes (May 21, 1870 – December 24, 1959) was an American investment banker and diplomat. He served as Governor-General of the Philippines from 1909 to 1913 and Ambassador of the United States to Japan from 1930 to 1932.He was the son of William Hathaway Forbes, president of the Bell Telephone Company, and wife Edith Emerson, a daughter of Ralph Waldo Emerson, nephew of James Grant Forbes and grandson of Francis Blackwell Forbes.