David C. O’Neal (January 24, 1937 – July 10, 2021) was an American politician and businessman. He was born in Belleville, Illinois.
O'Neal was the 41st Lieutenant Governor of Illinois, serving from 1977 to 1981 alongside Governor of Illinois James R. Thompson. For six years he served as Saint Clair County Sheriff. He was the first Republican to hold that office in twenty years.
In 1980, O’Neal sought the Republican nomination for the United States Senate winning the nomination to go on to the general election. His Democratic opponent was Illinois Secretary of State Alan J. Dixon. He lost the election to Dixon. O’Neal resigned as Lieutenant Governor in 1981.
O'Neal died on July 10, 2021 in Las Vegas, Nevada at the age of 84.