Charles O'Conor (January 22, 1804 – May 12, 1884) was an American lawyer who was notable for his career as a trial advocate and candidacy in the 1872 presidential election. He was the first Catholic presidential nominee. O'Conor retired in 1881, and settled in Nantucket, Massachusetts. He died there on May 12, 1884, and was buried at St. Patrick's Old Cathedral in New York City.