Cliff did radio spots asking for donations for the Salvation Army in 2002.
Cliff's personal hobby is collecting antique airplanes; he is a licensed and experienced sailplane pilot as well.
Cliff was originally considered for the role of Sam Loomis in Psycho (1960) by Alfred Hitchcock, but was passed over in favor of John Gavin.
Cliff has been married twice, to Cynthia Stone from 1957 to 1959, and Dina Merrill from 1966 to 1986.
Cliff co-starred with Joan Crawford portraying her character's much younger husband in Autumn Leaves (1956). According to Cliff, he was scared in showing up to meet Crawford, thinking that Joan would treat him unprofessionally because of his age, and was surprised when Joan greeted him wearing only a bathrobe and acting seductive when he entered the set.
Cliff discovered in February 1977 that a check due to him from Columbia Studios had his signature forged on it, after a notice from the IRS claiming he did not report it as income, with a photocopy of the cashed check that alerted him to the fraud, which he reported to the LAPD who in turn contacted the FBI. The forger turned out to be the head of Columbia Studios, David Bergman, who was arrested and convicted for embezzlement and forgery. The resulting scandal damaged Cliff's professional reputation for several years, until his re-entry into film in Brainstorm (1983).
Cliff was nominated for the Emmy for Outstanding Single Performance by an Actor in a Leading Role for his role in the United States Steel Hour episode "The Two Worlds of Charlie Gordon" in 1962 and won the Emmy for Outstanding Single Performance by an Actor in a Leading Role in a Drama for his role in the Bob Hope Presents The Chrysler Theatre episode "The Game" in 1966.
Cliff has a Motion Picture star at the Hollywood Walk of Fame at 6801 Hollywood Boulevard.
Cliff was nominated for that Golden Globe for Best Actor in a Drama for Charly (1969).
Cliff won the Oscar for Best Actor in a Leading Role for Charly (1968), in which he portrayed a mentally handicapped adult that was the subject of an experiment in intelligence-boosting. The film's script came from the popular short story "Flowers For Algernon."
Cliff portrayed Lieutenant John F. Kennedy in P.T. 109 after President Kennedy himself asked that he be cast in the role.
Cliff produced, directed, and acted in J.W. Coop (1972) and The Pilot (1981).
Cliff portrayed Playboy Magazine founder Hugh M. Hefner in Star 80 (1983).
Cliff has portrayed Peter Parker's Uncle Ben in all 3 Sony Pictures Spider-Man films.
Cliff was accidentally presumed dead after the December 7, 1941 Japanese attack of Pearl Harbor, where he was serving on a merchant rather than a naval vessel in the area at the time.
Cliff is 5 feet 11 inches tall.
Cliff: This isn't exactly a stable business. It's like trying to stand up in a canoe with your pants down
Cliff: The year you win an Oscar is the fastest year in a Hollywood actor's life. Twelve months later they ask, 'Who won the Oscar last year?'