It's a Mystery, Charlie Brown
- Aasta: 1974
- Riik: United States of America
- Žanr: Animation, Comedy, Family, TV Movie
- Stuudio: Lee Mendelson Film Productions, Bill Melendez Productions
- Märksõna: detective, dog, beagle
- Direktor: Phil Roman
- Osades: Todd Barbee, Melanie Kohn, Stephen Shea, Donna Le Tourneau, Jimmy Ahrens, Lynn Mortensen