Onyx: Kings of the Grail
- Anno: 2019
- Nazione: Spain
- Genere: Documentario, Storia
- Studio: Sevenfor
- Parola chiave: based on novel or book, holy grail, docudrama, semi-documentary, jesus christ
- Direttore: Roberto Girault
- Cast: Jim Caviezel, Maria de Medeiros, Anthony Howell, Ricard Sales, Maarten Dannenberg, Rafael Rojas