John O'Neill (December 17, 1822 – May 25, 1905) was an American lawyer and politician who served as a U.S. Representative from Ohio for one term from 1863 to 1865, Born in Philadelphia, O'Neill attended the common schools at Frederick, Maryland, and Georgetown College, Washington, D.C.

He moved to Zanesville, Ohio, in 1844 and commenced the practice of law.

He was United States Attorney for the Southern District of Ohio 1856-1858.

He then practiced law until his death in Zanesville, Ohio, on May 25, 1905.

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