This is the first film in the The Conjuring (2013) franchise in which Ed and Lorraine Warren are not featured or mentioned in any way.

David F. Sandberg was initially reluctant to direct the film, due to his general dislike of horror sequels. He changed his mind when it was clear he would be making a standalone prequel, with no major obligations to connect it to the larger franchise beyond a few brief references to the other films.

Originally scheduled to be released on May 19, 2017, but was moved to August 11, 2017 to avoid competition with Alien: Covenant (2017).

The design of the framework around the front door of the farmhouse shows regular crosses and upside down crosses, which may symbolize how there's both holy influence and dark forces at war in the home.

The woman who played the adult Annabelle Higgins is usually a stunt woman and has been a stunt for Vera Farmiga in the other Conjuring films. She also played the adult Annabelle Higgins in the first Annabelle film.

Alicia Vela-Bailey previously collaborated with David F. Sandberg on Lights Out.

The farm house was also used as Dolores's home in Westworld (2016).

Fred Tatasciore The voice behind the demonic voice in Annabelle creation also voices a popular character in a game called Overwatch, named Soldier 76

When Sister Charlotte shows Mr. Mullins her picture from Romania, Valak (from The Nun (2018)) can be seen in the darkness.

The doll that Janice, who now calls herself Annabelle, is given at the end of the movie is a replica of Raggedy Ann doll the Warren's removed during an exorcism. For the movie, a creepy looking porcelain doll was used to appear more sinister. This real doll is still kept on display, at Lorraine Warren's home, and can be seen in photos and footage of the Warren home.

The mask that Mrs. Mullins is wearing is most likely the same that is seen within the Warren's haunted objects room in The Conjuring (2013).

The shot of the bus passing Bea's cross as the girls leave the house is a flipped shot of the bus as it approaches the Mullins' house earlier in the movie.

When Linda goes to hide underneath the stairs and finds the Annabelle doll, you can see the eyes of the demon glowing in the dark behind the doll.