It's a Mystery, Charlie Brown
- वर्ष: 1974
- देश: United States of America
- शैली: Animation, Comedy, Family, TV Movie
- स्टुडिओ: Lee Mendelson Film Productions, Bill Melendez Productions
- कीवर्ड: detective, dog, beagle
- संचालक: Phil Roman
- कास्ट: Todd Barbee, Melanie Kohn, Stephen Shea, Donna Le Tourneau, Jimmy Ahrens, Lynn Mortensen