Otis William Caldwell (December 18, 1869 – July 5, 1947)[1] was an American botanist, college football coach and science writer.

[3] He was professor of botany at the Eastern Illinois State Normal School from 1899 to 1907.

While at Eastern Illinois, Caldwell served as head coach of the school's football team for three seasons, from 1899 to 1901.

Caldwell was Chairman of the Committee on Science of the Commission on The Reorganization of Secondary Education.

[5] He was director of the Lincoln School at Teachers College, Columbia University.