Ti West and Mia Goth collaborated on the script via FaceTime during a mandatory 2-week quarantine (due to the COVID-19 pandemic) in New Zealand prior to filming X (2022). They had only hoped A24 would agree to make the film. Fortunately, the project was green-lit before filming began on X.
To prepare for the tone of this movie, director/co-writer Ti West suggested that Mia Goth (Pearl) watch What Ever Happened to Baby Jane? (1962) and The Wizard of Oz (1939).
Tandi Wright, who plays Pearl's mother, was the intimacy coordinator on X (2022) and was offered the role of Ruth as the shoot on the first film was wrapping up. According to Ti West, she learned German for the role in a hurry and became so convincing in her accent that she fooled two German members of the crew.
Originally meant to be filmed in black and white, but A24 were against it, so it was made in extremely vivid color. Mia Goth claims another reason for the switch from black and white to bright colors was that the team felt like films being made in that way had "become its own thing", and she and Ti West wanted to do something "different and unique".