Achttien jaar voor de gebeurtenissen van deel 1 en 2 volgen we Katie en haar zus Kristi in het huis van hun ouders. Na verloop van tijd merkt Dennis dat Kristi zich raar begint te gedragen nadat ze heeft beweerd een onzichtbare vriend te hebben, genaamd Toby. Op aanraden van Randy plaatst Dennis een aantal camera's in het huis om te zien of er ook echt iets rondspookt. Ze doen een schokkende ontdekking...
Nee, helaas is Paranormal Activity 3 nog niet beschikbaar op Netflix in Nederland.
| Sound | Michael Hertlein | Dialogue Editor |
| Production | Billy Stimson | Production Assistant |
| Crew | Daniel Browning Smith | Stunts |
| Camera | Daniel C. McFadden | Still Photographer |
| Crew | Emily Brobst | Stunt Double |
| Crew | Kelli Barksdale | Stunts |
| Crew | Ator Tamras | Stunt Double |
| Crew | Liisa Cohen | Utility Stunts |
| Costume & Make-Up | Ryan Lennon | Costumer |
| Crew | James G. Brill | Transportation Coordinator |
| Sound | Margit Pfeiffer | Foley Editor |
| Crew | Meegan E. Godfrey | Stunts |
| Camera | Olga Matlin | Grip |
| Lighting | Derek Touvell | Electrician |
| Crew | Jason Messersmith | Transportation Captain |
| Crew | Nicholas King | Stunts |
| Crew | Lynn Johnson | Set Medic |
| Production | Erin Vitali | Production Assistant |
| Sound | Tim D. Lloyd | Boom Operator |
| Production | Alexa L. Fogel | Casting |
| Production | Sarah Domeier Lindo | Casting Assistant |
| Crew | Pablo C. Herrera | Craft Service |
| Directing | James Moran | First Assistant Director |
| Sound | Daniel S. Irwin | Dialogue Editor |
| Crew | James Armstrong | Stunts |
| Crew | Chris J. King | Stunts |
| Crew | Hernan Hernandez | Craft Service |
| Directing | Jaysene Overton | Second Second Assistant Director |
| Crew | Meegan E. Godfrey | Stunt Double |
| Directing | Marc Newland | Second Assistant Director |
| Crew | Seth Duhame | Stunt Double |
| Production | Claire Simon | Casting |
| Sound | Zsolt Magyar | Sound Mixer |
| Crew | Michael R. King | Stunts |
| Crew | Nikki Hester-Jose | Stunt Double |
| Crew | Steven Stone | Stunts |
| Camera | Keith Dunkerley | Camera Operator |
| Production | Murray Miller | Location Manager |
| Directing | Matt Smith | Second Second Assistant Director |
| Sound | Paul Stevenson | Foley Artist |
| Crew | Craig Jensen | Stunts |
| Costume & Make-Up | Rebecca M. Graves | Costumer |
| Sound | Stephen P. Robinson | Sound Designer |
| Production | Christine Kromer | Casting |
| Production | David Thornsberry | Location Manager |
| Production | Oren Peli | Producer |
| Writing | Christopher Landon | Writer |
| Directing | Henry Joost | Director |
| Editing | Gregory Plotkin | Editor |
| Directing | Ariel Schulman | Director |
| Production | Jason Blum | Producer |
| Art | Jennifer Spence | Production Design |
| Production | Steven Schneider | Producer |
| Art | Kelly Berry | Set Decoration |
| Costume & Make-Up | Leah Butler | Costume Design |
| Production | Terri Taylor | Casting |
| Production | Christopher Landon | Co-Producer |
| Crew | Robert Malina | Visual Effects Editor |
| Production | John McAlary | Casting Associate |
| Crew | Zachery Alexander | Property Master |
| Costume & Make-Up | Renee J. Vaca | Hair Department Head |
| Visual Effects | Jamie Dixon | Visual Effects Supervisor |
| Costume & Make-Up | Linda Huse | Costume Supervisor |
| Costume & Make-Up | Paula Jane Hamilton | Makeup Artist |
| Crew | Thomas Mertz | Special Effects Coordinator |
| Costume & Make-Up | Kymber Blake | Makeup Department Head |
| Directing | Diane Weiss | Script Supervisor |
| Visual Effects | Michelle Eisenreich | Visual Effects Producer |
| Camera | Magdalena Górka | Director of Photography |
