Fall TV Preview

New Girl Scoop: It's Always Sunny's Kaitlin Olson Joins Cast as Jess' Nemesis — and [Spoiler]'s Fiancée

New Girl Season 4 Kaitlin Olson

 It’s Always Sunny in Philadelphia‘s Kaitlin Olson is about to cause a perfect storm on New Girl.

The actress is set to recur in Season 4 of the Fox comedy as Ashley, Jess and Cece’s onetime high school nemesis who is now engaged to Jess’ father Bob (returning guest star Rob Reiner), TVLine has learned.

RELATED New Girl Promotes [Spoiler] to Series Regular

Olson, who joins previously announced Season 4 Newbies Jessica Biel and Reid Scott, will debut in Episode 3, which is slated to air in late September.

New Girl‘s fourth season kicks off Tuesday, Sept. 16 at 9/8c.