- Awesome, Dear Boy: Imogen Poots accepted because she loved the idea of working with a mostly all-female crew.
- California Doubling: The film is set on an American college campus, but was filmed in New Zealand - primarily around Dunedin and Oamaru - with the University of Otago serving as Hawthorne College.
- Christmas Rushed: The film's production was incredibly rushed, with everything happening in five months to get it ready for a Christmas release. Due to the rushed nature of the shoot, some scenes could only have time to be done in one take.
- Dawson Casting: Imogen Poots (Riley) had turned 30 only three weeks before filming began, putting her about a decade past the typical college age range (though she certainly didn't look 30). Contrast that with Brittany O'Grady (Jesse), who had turned 23 (around the typical age of a college senior) one day before Poots' birthday.
- Dear Negative Reader: Sophia Takal fended off the backlash that the film was too preachy by saying she put "message before plot."
- Fake American: Imogen Poots is British putting an American accent for Riley.
- Missing Trailer Scene: In the trailer, the scene with Helena brushing her teeth has the killer CGI'd into the shot. In the actual scene in the film, she's alone.
- Not Screened for Critics: The movie had a review embargo that lasted until its release date.
- What Could Have Been:
- Sophia Takal originally pitched a remake of I Spit on Your Grave, but was then offered to remake Black Christmas instead.
- Sophia Takal apparently cut thirty minutes worth of footage to make the film PG-13 - so as to market to young female horror fans.
- Gloria Steinem was offered a cameo, which she turned down because there wasn't a completed script.
Trivia / Black Christmas (2019)