William Cornelius Sullivan (May 12, 1912 – November 9, 1977) was a Federal Bureau of Investigation official who directed the agency's domestic intelligence operations from 1961 to 1971. Sullivan was forced out of the FBI at the end of September 1971 due to disagreements with FBI director J. Edgar Hoover. The following year, Sullivan was appointed as the head of the Justice Department's new Office of National Narcotics Intelligence, which he led from June 1972 to July 1973. Sullivan died in a hunting accident in 1977. His memoir of his thirty-year career in the FBI, written with journalist Bill Brown, was published posthumously by commercial publisher W. W. Norton & Company in 1979.