Clyde Klein (1930-) was an American FBI agent who was based in New York City during the 1970s. In 1971, he helped NYPD detectives Jimmy Doyle and Buddy Russo investigate the "French Connection" conspiracy theory by tailing the French drug trafficker Alain Charnier from New York to Washington DC, where he found him negotiating with the Mafia caporegime Salvatore Boca on Capitol Hill.