Faris said last October that she was open to appearing in director Malcolm Lee's upcoming sequel, but disclosed in a new interview that she ultimately decided against taking part in the project.
"No, I don't think I'm going to do it," the actress told Coming Soon.
She further explained: "I don't think I'm part of [the sequel]. I don't know exactly what's happening with it, but I hear it's sort of in the works and stuff."
The Weinstein Company has confirmed that Scary Movie 5 will likely be released on January 1, 2013, but little else is known about the project.
Faris is currently starring with Sacha Baron Cohen in The Dictator, opening on May 16 in US and UK cinemas.