One of the most popular teen dramas, “The O.C.,” celebrates its 15th anniversary today. The show, created by Josh Schwartz, premiered on Fox on Aug. 5, 2003, and ran for four seasons. Throughout that time, it helped its main cast —Benjamin McKenzie, Adam Brody, Mischa Barton, Rachel Bilson and more — make names for themselves, but it also had a lot of guest stars who went on to have quite the careers, too.

Here are 14 “The O.C.” guest stars who went on to become famous.

Chris Pratt

After he finished up on The WB’s “Everwood,” Pratt starred as Ché throughout Season 4 of this Fox series. He’s now known for his role of Andy Dwyer on “Parks and Recreation” and for his huge “Guardians of the Galaxy” and “Jurassic World” franchises. Coincidentally enough, before bringing Star-Lord to 2018’s “Avengers: Infinity War,” Pratt’s first episode of “The O.C.” was titled “The Avengers.”

Bella Thorne

She starred on her own Disney Channel show, “Shake It Up,” her own Freeform series, “Famous in Love,” and has been in quite a few movies over the years, but in 2007, Thorne played a young Taylor Townsend in Season 4, Episode 13 of “The O.C.”

Shailene Woodley

The “Divergent” star was the original Kaitlin Cooper on “The O.C.” until Willa Holland took over the role later in the series. Woodley had her hands full just a few years later with “The Secret Life of the American Teenager,” the “Divergent” franchise, “The Fault in our Stars” and now, her HBO show, “Big Little Lies.”

“Pretty Little Liars” alums Lucy Hale, Janel Parrish and Ashley Benson

Years before they’d join together on ABC Family for seven seasons of “Pretty Little Liars,” Hale, Parrish and Benson all had roles on “The O.C.” Hale was by herself in a Season 3 episode, while Parrish and Benson played best friends in a Season 4 episode.

pll oc Lucy Hale, Janel Parrish, Shay Mitchell and Ashley Benson attended the Teen Choice Awards 2015 at the USC Galen Center on Aug. 16, 2015 in Los Angeles. Mitchell was the only one of them to not be on “The O.C.” Photo: Kevin Winter/Getty Images

Paul Wesley

He was recently cast on CBS All Access’ new series “Tell Me a Story” after years of portraying Stefan Salvatore on The CW’s “The Vampire Diaries,” but before all of that he was Donnie in a Season 1 episode of this Fox drama.

“Twilight” stars Nikki Reed, Cam Gigandet and Jackson Rathbone

Before they all had parts in the popular “Twilight” franchise, they each showed up on “The O.C.” Reed was Sadie Campbell in six Season 3 episodes, while Gigandet played the dangerous Volchok in Seasons 3 and 4. In addition, Rathbone took on the role of Justin in Season 3 for two episodes.

Max Greenfield

Towards the end of his run as sweet Deputy Leo on “Veronica Mars,” but years before he was set to become the fan-favorite Schmidt on “New Girl,” Greenfield played a young Sandy Cohen in a Season 4 episode of “The O.C.”

max greenfield oc Max Greenfield attended the Sharewell/Zimmer Children’s Museum Discovery Award Dinner at Skirball Cultural Center on Nov. 15, 2017 in Los Angeles. Photo: Rachel Murray/Getty Images for Sharewell/Zimmer Children's Museum

Jeffrey Dean Morgan

A few months before “Supernatural,” which he played John Winchester on, premiered, Morgan was in a Season 2 episode of “The O.C.” From there, he went on to star in a few romance films, play Denny on “Grey’s Anatomy” and then start his time on “The Walking Dead” as Negan.

Olivia Wilde

People now know Wilde for playing Thirteen on the medical drama “House” from 2007 to 2012, as well as for her work on movies like “People Like Us,” “Her” and “Love the Coopers,” but she also played Alex Kelly on “The O.C.” for more than 10 episodes.

Amber Heard

She’s getting ready to have her superhero movie “Aquaman” come out in theaters, but Heard has quite the acting resume. She was in a 2005 episode of “The O.C.” before going on to be in projects like “Never Back Down,” “Pineapple Express” and “Magic Mike XXL.”