John Henry O'Neall (October 30, 1838 – July 15, 1907) was an American lawyer and politician who served two terms as a U.S. Representative from Indiana from 1887 to 1891.

Born in Newberry, South Carolina, O'Neall was left an orphan at eight years of age and was raised by his grandfather, who lived in Daviess County, Indiana.

He attended country schools and graduated from Indiana University Bloomington in 1862.

He then graduated from the law department of the University of Michigan at Ann Arbor in 1864.

This article incorporates public domain material from the Biographical Directory of the United States Congress