Elmer Ellis (July 27, 1901 – August 27, 1989) was an American educator and fourteenth president of the University of Missouri, from 1955 to 1966, and first president of the University of Missouri System. He was instrumental in the expansion of the university to include the University of Missouri-Kansas City and University of Missouri-St. Louis.Ellis Library is named in his honor.
Raised in North Dakota, Ellis joined the department of history at the University of Missouri in 1930. He became a full professor in 1940, and by 1945 rose to be the dean of the university's college of arts and sciences. In 1955, he was named acting president, and became the permanent president later that year.
He also served on the Department of the Army Historical Advisory Committee from 1954-1956.