Director Damien Leone said that several big studios showed interest in financing this movie based on the unexpected success of Gã Hề Điên Loạn (2022), even without a full script, but he turned them all down because he is certain that they would never let him film the opening scene alone, which he describes as "very controversial". Leone commented that the only reason that he can be so uncompromising in his depiction of horror and gore is because he finances his movies independently, creates all the special effects himself to keep costs down, and has no big studio breathing down his neck to make the movie more mainstream.
The first horror film since Lưỡi Cưa 3 (2006) to receive the "18" rating in France (no one under 18 admitted, equivalent to NC-17 in the U.S.)
Clint Howard is in this film and also featured in Initiation: Silent Night, Deadly Night 4 (1990) and Silent Night, Deadly Night 5: The Toy Maker (1991), which featured a slasher killer dressed as Santa Claus, something this film pays homage to.
When making Terrifier 1 & 2 Damien Leone has stated in interviews that the crew consisted of only 5-10 people depending on the day with crew members working every position possible. For Terrifier 3 there was over 50 people on set every day with dedicated crew departments.
In one scene a woman is seen reading a book called "The 9th Circle" by an author called Rosemary Castavete. This is a reference to both the original short film where Art The Clown first appeared The 9th Circle (2008) and Rosemary's Baby (1968) which features the titular character Rosemary and also characters with the surname Castavete.