De film speelt zich af na de gebeurtenissen uit 'Insidious: Chapter 3'. Nadat Elise Rainier de familie Brenner heeft geholpen begint ze samen met Specs en Tucker een eigen bedrijf met de naam "Spectral Sightings".
Ja! de film Insidious: The Last Key is nu beschikbaar om te kijken op Netflix in Nederland.
| Crew | Emily Brobst | Stunts |
| Crew | Cassandra McCormick | Stunts |
| Production | Jim Small | Assistant Location Manager |
| Directing | Adam Robitel | Director |
| Writing | Leigh Whannell | Writer |
| Camera | Aaron A. Goffman | Additional Photography |
| Art | Aaron A. Goffman | Property Master |
| Crew | Meegan E. Godfrey | Stunts |
| Production | Jason Blum | Producer |
| Production | Oren Peli | Producer |
| Production | James Wan | Producer |
| Sound | Joseph Bishara | Original Music Composer |
| Writing | Leigh Whannell | Characters |
| Art | Melanie Jones | Production Design |
| Production | Brian Kavanaugh-Jones | Executive Producer |
| Production | Couper Samuelson | Executive Producer |
| Production | Terri Taylor | Casting |
| Production | Bailey Conway | Executive Producer |
| Art | Sandra Skora | Set Decoration |
| Production | Laura Altmann | Associate Producer |
| Editing | Timothy Alverson | Editor |
| Production | Dan Lazarovits | Associate Producer |
| Camera | Toby Oliver | Director of Photography |
| Production | Jeanette Volturno | Co-Producer |
| Production | Phillip Dawe | Co-Producer |
| Production | Steven Schneider | Executive Producer |
| Production | Charles Layton | Executive Producer |
| Art | Hunter Brown | Art Direction |
| Production | Leigh Whannell | Producer |
| Costume & Make-Up | Lisa Norcia | Costume Design |
| Production | Rick Osako | Co-Producer |
| Costume & Make-Up | Todd Tucker | Special Effects Makeup Artist |
| Crew | Jennifer Scudder Trent | Post Production Supervisor |
