John O'Neal(l) may refer to:

• John O'Neal (Medal of Honor) (born 1841), U.S. sailor who was awarded the Medal of Honor
• John O'Neal (politician) (active since 2010), American politician in West Virginia
• John H. O'Neall (1838–1907), American politician from Indiana
• John Belton O'Neall, judge who served on the precursor to the South Carolina Supreme Court
• Johnny O'Neal (born 1956), American pianist

• John O'Neil (disambiguation)
• John O'Neill (disambiguation)