Charles Sumner Hamlin (August 30, 1861 – April 24, 1938) was an American lawyer and politician who served as the first chairman of the Federal Reserve from 1914 to 1916. He previously served as the United States assistant secretary of the treasury from 1893 to 1897, and again from 1913 until 1914 when President Woodrow Wilson nominated him as one of the original members of the Federal Reserve Board. After his term as chairman, Hamlin continued to serve on the Board through 1936.