John Haskell Hewitt (August 8, 1835 – October 8, 1920) was an American classical scholar and educator, notable for serving as acting president of Williams College from 1901 to 1902. Born in Preston, Connecticut to Charles Hewitt and Eunice (Witter), Hewitt entered Yale University in 1855, initially intending to study law. While at Yale he befriended Franklin Carter, a relationship that would prove beneficial in later years. After graduating with an A.B. in 1859, Hewitt then earned an advanced degree from the Yale Divinity School in 1863. He served as a librarian at Yale's Brothers in Unity Library until 1865, until he accepted a position teaching Latin and Greek at Olivet College. He became a full professor the same year, and earned a Masters Degree from Yale in 1867.