"Salma is truly a gifted talent and an incredible force in our industry," Teri Weinberg, NBC Entertainment's executive vice president, said in a statement. "I've had the privilege of working with her and I can't wait to see what comedic sparks fly with our brilliant '30 Rock' cast."
"I have been a fan of Tina's talent, both as an actress and a writer, since working with her years ago on 'SNL.' I am so excited to be part of such an intelligent, funny show, as well as working with the brilliant Alec Baldwin and the rest of the cast of '30 Rock,'" Hayek said.
"Salma is smart, funny, and gorgeous. I think she will be a great strong presence opposite Jack Donaghy," Fey said.
Hayek's screen credits include "Desperado," "From Dusk Till Dawn," "Dogma" and "Frida." She is also an executive producer on the television series "Ugly Betty."
The new season of "30 Rock" is scheduled to premiere Oct. 30.