Charles O'Neill

• Charles O'Neill (musician), Canadian bandmaster, composer, organist, cornetist, and music educator
• Charles O'Neill (Pennsylvania politician), U.S. Representative from Pennsylvania
• Charles O'Neill (engineer), Australasian philanthropist and politician
• Charles H. O'Neill, U.S. politician
• Charles O'Neill, 1st Earl O'Neill, Irish politician, peer and landowner
• Charles O'Neill (Irish nationalist politician), Member of Parliament for South Armagh, 1909–1918