Jack may refer to:
- Jack Canna: A counterfeiter from the The New Scooby-Doo Movies episode The Haunted Showboat.
- Jack Angel: An American voice actor.
- Jack: A tour guide in the Scooby-Doo and Scrappy-Doo (1st series) episode I Left My Neck in San Francisco.
- Jack Marsten: The owner of Overview Hotel from the The New Scooby-Doo Mysteries episode Doom Service.
- Jack: The real identity of BooBeard from the A Pup Named Scooby-Doo episode Ghost Who's Coming to Dinner.
- Jacques, French pronunciation of Jack: A friendly ferry driver who turned out to be an evil werecat, from the DTV film Scooby-Doo on Zombie Island.
- Jack: The owner of Oakhaven Restaurant in the DTV film Scooby-Doo! and the Witch's Ghost.
- Jack: A member of Bad Omens from the DTV film Scooby-Doo! and the Legend of the Vampire.
- Jack Hunter: The founder of Huntersville in the What's New, Scooby-Doo? episode Simple Plan and the Invisible Madman.
- One-Eyed Jack: A pirate from DC Comics' Scooby-Doo! story Yo Ho Haunted.
- Jack Riggins: The culprit behind the Fortius robot in the DTV short film Scooby-Doo! Spooky Games.
- Jack Rabble: The real identity of Mr. Hyde from the DTV film Scooby-Doo! Mask of the Blue Falcon.
- Jack: An actor who played Jacques in Zombie Teenagers and the Island of Doom in Scooby-Doo! Return to Zombie Island.