Richie is best known for her work on the reality show "The Simple Life," in which she co-starred with Paris Hilton. Richie recently gave birth to her first child, a daughter named Harlow.
"Nicole auditioned for the part and was very funny," executive producer Josh Schwartz said in a statement. "This role is a great opportunity for her to show off her comedic skills and be diabolically evil and kick some butt. It's going to be really fun."