The real Watergate informant who helped inspire The X-Files character Deep Throat was Mark Felt.
In the Watergate scandal, Felt was the FBI’s associate director and secretly supplied information to Washington Post reporters Bob Woodward and Carl Bernstein. His identity remained hidden for decades, and he was publicly identified as “Deep Throat” in 2005.
The X-Files used that famous nickname for a mysterious government informant who fed Fox Mulder information about paranormal investigations. The fictional character was played by Jerry Hardin and served as a bridge between Mulder and the shadowy conspiracy surrounding the X-Files.
A common mix-up is confusing Felt with Woodward or Bernstein. They were the journalists who received the leaks, not the informant himself. The fictional character also drew inspiration from Donald Sutherland’s informant character X in the film JFK, so the television version is not a literal portrayal of Felt.