John O'Neill was a U.S. Representative from Ohio.
Education
Born in Philadelphia, O'Neill attended the common schools at Frederick, Maryland, and Georgetown College, Washington, D.C. He was graduated from Mount St. Mary's College, Emmitsburg, Maryland, and from the law department of Georgetown College, Washington, D.C., in 1841.
Career
He was admitted to the bar in 1842. He moved to Zanesville, Ohio, in 1844 and commenced the practice of law. He served as the prosecuting attorney of Muskingum County in 1845.
He also held various county offices. O'Neill was elected as a Democrat to the Thirty-eighth Congress (March 4, 1863 - March 3, 1865). He resumed the practice of his profession.
He then practiced law until his death in Zanesville, Ohio, on May 25, 1905. He was interred in St. Thomas' Cemetery.
Membership
He served as member of the Ohio Senate 1883-1885.