Deep Throat is the pseudonym given to the secret informant who provided information in 1972 to Bob Woodward, who shared it with Carl Bernstein. Woodward and Bernstein were reporters for The Washington Post, and Deep Throat provided key details about the involvement of U.S. president Richard Nixon's administration in what came to be known as the Watergate scandal. In 2005, 31 years after Nixon's resignation and 11 years after Nixon's death, a family attorney stated that former Federal Bureau of Investigation (FBI) Associate Director Mark Felt was Deep Throat. By then, Felt was suffering from dementia and had previously denied being Deep Throat, but Woodward and Bernstein then confirmed the attorney's claim.

William Mark Felt Sr. was an American law enforcement officer who worked for the Federal Bureau of Investigation (FBI) from 1942 to 1973 and was known for his role in the Watergate scandal. Felt was an FBI special agent who eventually rose to the position of Deputy Director, the Bureau's second-highest-ranking post. Felt worked in several FBI field offices prior to his promotion to the Bureau's headquarters. In 1980, he was convicted of having violated the civil rights of people thought to be associated with members of the Weather Underground, by ordering FBI agents to break into their homes and search the premises as part of an attempt to prevent bombings. He was ordered to pay a fine, but was pardoned by President Ronald Reagan during his appeal.