All The Celebrity Cameos You Forgot On 'Gossip Girl'

Real Housewives of New York star — and one of NYC’s original It Girls — Tinsley Mortimer starred as herself. Mortimer is introduced as a friend of Lily van der Woodsen in season two.

The “Girls Just Want To Have Fun” singer surprised everyone when she appeared as a party guest at Blair Waldorf’s birthday in season two.

Also appearing in season two was Liukin, who traded her Olympic medals for a ticket to the Snowflake Ball where she flirted with the dreamy (and problematic) Chuck Bass.

Before becoming one of Hollywood's most controversial celebrities, Hammer played Gabriel Edwards in season two of Gossip Girl. Edwards was one of Serena van der Woodsen’s love interests.

In season three, Hilary Duff guest starred as Olivia Burke, a famous actress and NYU freshman. In one of Gossip Girl’s most chaotic moments, Burke has an impromptu threesome with Dan Humphrey and Vanessa Abrams.

Season three also featured supermodel Tyra Banks as Ursula, a rising actress who Serena befriends while working as a publicist.

The Victoria’s Secret model appeared as herself in season four, going as Lily’s guest to a fashion event.

The Project Runway star appeared in an episode of season four when Jenny Humphrey meets him for a coveted job interview.

Wang played herself, designing Blair's wedding dress before she married Prince Louis Grimaldi in season five.

Bell was the mysterious voice of Gossip Girl throughout the series, and finally made a guest appearance in the final episode.