NEW YORK – Hilary Duff is joining the cast of “Gossip Girl” but not on a regular basis.

The CW series’ spokeswoman, Melissa Burton, says the 21-year-old singer and actress will guest-star next season as “a movie star looking for a typical college experience.”

Duff’s character, named Olivia Burke, enrolls at New York University and becomes roommates with “Gossip Girl” hipster Vanessa, portrayed by Jessica Szohr (ZOR).

Oh, what a tangled web: Burton says Olivia will spark a romance with aspiring novelist Dan, played by Penn Badgley. As fans know, Vanessa used to have eyes for Dan then they dated other people.

Duff begins her “Gossip” arc on Oct. 5.

Season three premieres Sept. 14, as the prep kids head off to college.