Tyler Dennett (b. June 13, 1883, Spencer, Wisconsin; d. 1949) was an American historian and educator. He is best known for his book John Hay (1933), for which he won the 1934 Pulitzer Prize for biography.
In 1900, Dennett enrolled at Bates College, then transferred to Williams College as a sophomore. After his graduation in the spring of 1904 and a year of work in Williamstown, he attended the Union Theological Seminary, where he was awarded a diploma in 1908. He served briefly as a Congregational Minister, but soon left to pursue a career in journalism. In 1922 he published Americans in Eastern Asia, a study of American policy in the Far East, which was well received and was long held as an important work in the field. Dennett was awarded a Ph.D. in history from Johns Hopkins University in 1925, doing research on Theodore Roosevelt and the Russo-Japanese War.
He taught American history at Johns Hopkins University (1923–24) and at Columbia University (1927–28), and international relations at Princeton University (1931–34). Dennett served as president of Williams College
Among his numerous scholarly writings was The Democratic Movement in Asia (1918).