Cuarto milenio (series)
- User score: 7.5
- Production country: Spain
- Creator: Iker Jiménez
- Production companies: Mediaset España, Alma Producciones Digitales
- Genre: Reality, Mystery
- Release date: 11/13/2005
- Release date of last episode: 10/6/2024
- Series status: Returning series
- Seasons count: 20 ( List of episodes )
- Episodes count: 809
- Run time: 120 min.
