Maxine's "Oui" shirt is a reference to Oui, a men's adult pornographic magazine published in the United States featuring explicit nude photographs. Oui ceased publication in 2007.
When Molly Bennet (Lily Collins) talks to Maxine outside of her trailer, she says that actresses have to stick together, similar to what Mitsy (Emma Jenkins-Purro) says to Pearl about sisters in law sticking together in Pearl (2022).
MaXXXine was originally developed as the end of the X trilogy. Ti West later stated in February 2024 that he has plans for a fourth film, which would depend on the third film's reception. In May 2024, West confirmed that he was working on a fourth film and that he may develop it as his next project. In August 2024, in a Reddit Ask-Me-Anything, he said he's happy with where he left it and may have it remain a trilogy.
When Lebat is chasing Maxine through the movie studio backlot, at one point they exit through the main doors of the clock tower, as prominently featured in Back to the Future. Back to the Future is set in 1985, just like MaXXXine.
Mia Goth is the granddaughter of Brazilian actress Maria Gladys. As Goth became more popular in Brazil, this became a popular curiosity and ended up going viral. Marketing for this film in Brazil decided to exploit this and "The granddaughter of Brazilian actress Maria Gladys" succeeded Goth's name whenever it was mentioned while promoting the movie despite Gladys having no connection to it.