Former O.C. star Willa Holland is to appear in The CW's Gossip Girl for a three-episode guest stint.

The actress, who played Marissa Cooper's younger sister Kaitlin on the hit drama series, will take on the role of 16-year-old model Agnes in the new season. Her character is introduced when she starts working for Blair's mother Eleanor Waldorf (Margaret Colin).

Meanwhile, John Patrick Amedori has been cast as Aaron Rose, a new love interest for lead character Serena (Blake Lively), according to E! Online. As well as starring in The Butterfly Effect, he has also appeared in a variety of US dramas, including Law & Order, Nip/Tuck and Ghost Whisperer.

Gossip Girl's second season premiered on Monday in the US. It will continue for a full 24-episode run.

digitalspy.co.uk

I still like the books better lol

Yay! I expect a bitchy character not unlike Kaitlin cause Willa plays it so well.

The O.C >> Gossip Girl

^totally agree
The OC >>>>>> any other teen series

WILLA IS THE BEST BITCH EVER!! i so love her on The OC Kaitlin rocks! ..i hope Autumn Reeser will have future projects too

I miss Mischa

^well she rejects good projects coming on to her ..and her recent movies didn't do so well

omg she's gonna be Georgina in Jenny's life

Speaking of Georgina, is she ever returning this season?

^i don't know ..maybe ..i think it's a surprise

you know i'm thinking about she'll come back with Nate, just like in the book ..maybe now she's at Boot Camp, Nate will meet her there ..you know just like in the book ..it's very weird that Nate doesn't know her in the tv series

I loved her as Kaitlin.

She will hang with Jenny? Funny, I always thought they look similar, lol.

^yea ..but not that much ..Willa all the way

Willa is FAR more beautiful, that's for sure.

OMG!!! Im totally in love with Willa..She is so amazing. i loved her as Kaitlin..
Gosh, i miss O.C so much. its one of the best Teen shows. It was so funny, and yet sad..
I want O.C!!!!

Yeah Willa was sooo good as Kaitlin. Off...I miss the OC too, my sexy Julie Cooper...aaa, i loved those 3 coopergirlzz, they were soo hot.

But I am excited to watch gossip girl next year finally in german tv, is it as good as the oc was?

i know she's gonna play the bad girl ..but i wanna see something different ..her role on the movie "Garden Party" is just so much like Kaitlin

I love Julie too..She was one of my favorites!