Olivia Wilde, Rachel Bilson and Ben McKenzie are among the celebrities who have remembered the TV show The OC on its 20th anniversary.

American teen drama The OC first aired in 2003 and it starred actors including Guardians Of The Galaxy’s Chris Pratt and Divergent actress Shailene Woodley.

The show follows a group of friends who live in the upper-class neighbourhood of Newport Beach, Orange County, California.

In The OC, McKenzie, 44, plays Ryan Atwood, a teenager who is taken in and adopted by the Cohen family.

Remembering the show, McKenzie posted a photo of himself to Instagram with actor Adam Brody, who played Seth Cohen.

The post said: “The OC premiered 20 years ago today.

“I keep showing my kids pics to prove how cool I used to be, but for some reason they don’t seem to get it.”

Bilson, 41, also posted a photo to her Instagram with the simple caption “Twenty”.

The actress played Summer Roberts, who had a love interest in Brody’s character Cohen.

Director of Don’t Worry Darling Wilde, 39, also reminisced on the show and reposted a photo of herself with Mischa Barton to her Instagram story.

Wilde said: “Ok I see it’s (The OC) having a moment because it premiered 20 years ago.”

She added “Mischa = One of the most beautiful faces I’ve ever seen. I remember just being like whoooaaaaa.”

Wilde had played Alex Kelly, who dates Cohen and Barton’s character Marissa Cooper.

Melinda Clarke, who starred as Julie Cooper in the show, posted a photo of herself and Peter Gallagher (Sandy Cohen) to her Instagram, and could not seem to believe how old the show was.

She said: “Wait Whut?! We’re how old? #20yearstoday #foreveryoung.”

Josh Schwartz, creator and executive producer of The OC, reposted a photo from the show to his social media which said: “Yes I am feeling old. Thanks.”