Prime Time Drama Gossip Girl: Katie Cassidy IN! June 26, 2010 Gigi Leave a comment Zap2It is reporting that Melrose Place hottie Katie Cassidy will be guest starring on Gossip Girl as a Columbia student who is a love interest for Nate Archibald. Be Sociable, Share! Tweet Related posts: Hot Chick of the Week: Katie Cassidy The Baddest Bitch: Gossip Girl’s Georgina Gossip Girl Returns! New Promo! The Gossip Girl Manga: XOXO OLTL’s Bree Williamson is a Gossip Girl!