'The O.C.' Star Mischa Barton Joins 'The Hills' Revival

Early-aughts television will soon collide when The O.C. star Mischa Barton joins the upcoming [...]

Early-aughts television will soon collide when The O.C. star Mischa Barton joins the upcoming revival of The Hills, with MTV revealing the news on Wednesday, Oct. 3.

It had previously been rumored that MTV would be adding new faces to its reboot of the beloved reality series, and Barton's casting confirms the speculation. Barton is best known for her time on The O.C. from 2003-2006, as well as her roles in movies, including The Sixth Sense and Notting Hill.

The actress will join the show's original cast members Audrina Patridge, Brody Jenner, Frankie Delgado, Heidi Pratt, Jason Wahler, Justin "Bobby" Brescia, Spencer Pratt, Stephanie Pratt and Whitney Port for the reboot, which is titled The Hills: New Beginnings.

Other newcomers to the show include Kaitlynn Carter, Jennifer Delgado, and Ashley Wahler, Vulture shares.

Port offered a few details about the revival in an interview with The Hollywood Reporter, admitting that she's a bit nervous to return to reality television now that she has a family.

"Initially, I was scared," she said. "I had reservations at first because I have a family now and more to protect than when I was 25 years old. I really had to think about it."

Still, Port noted that she's "nervous, but also excited."

Noticeably absent from the reboot are Lauren Conrad and Kristin Cavallari, each of whom have their own reasons for declining to appear.

A source told PEOPLE that Conrad's priorities have changed since her time on reality television and that she has nothing but good wishes for her former castmates.

"She's in a different place in her life," the source said. "But she wants everyone to enjoy themselves. She wishes everyone the best."

"She loves being a mother and focusing on her family and on her work," the insider added. "She has a very full and happy life."

After concluding her reality TV career, Conrad became a lifestyle guru, starting a website and fashion line for Kohl's. She's also mom to 1-year-old son Liam, whom she shares with husband William Tell.

As for Cavallari, her return to the MTV show would be a bit of a conflict of interest, as she currently headlines her own E! reality show, Very Cavallari, alongside husband Jay Cutler.

"She can't do the show because she has a contract with E!" a source told PEOPLE of the mom of three. "But she's still close with Heidi [Montag] and Spencer [Pratt] and is excited for them."

Photo Credit: Getty / Jackson Lee