C. William O'Neill[1] (February 14, 1916 – August 20, 1978) was an American judge and Republican politician, who served as the 59th governor of Ohio.

He was defeated for re-election due to his support of the controversial proposed "right to work" amendment to the Ohio Constitution.

O'Neill was the only Ohioan to serve in top leadership positions in the legislative, executive and judicial branches of Ohio.

He died on August 20, 1978, and his funeral service was at First Community Church in Columbus.

Additionally, The C. William O'Neill Senior Citizens Center in Marietta, Ohio is named in his honor.