Blake Lively Celebrates ‘Gossip Girl’ Turning 18 with Sweet Throwback Photos

Blake Lively is feeling nostalgic as she marks a special birthday.

On Sunday, Sept. 21, the 38-year-old actress took to Instagram to share a post celebrating the 18th anniversary of her hit series Gossip Girl.

Lively brought It girl Serena van der Woodsen to TV screens across the globe in the hit show, which premiered in September 2007. She maintained her lead role alongside costars such as Leighton Meester, Penn Badgley, Chace Crawford and Ed Westwick through to the sixth and final season, which aired in 2012.

On Instagram, Lively shared a multitude of behind-the-scenes images from her time with the Upper East Siders

“The summer gossip girl turned 18…” she captioned the post.

She continued, writing, “This show was my college. It was my education, my social life, my hardwork, my late nights and early mornings, my teacher. New York City and Silvercup Studios (& sometimes Paris ✨) was my campus for SIX years.”

“So many memories. What. A. Decade. 💖 What a University,” Lively concluded.

Lively took fans behind the curtain of the popular show, offering a glimpse at what it was like to film with her costars.

She notably shared a photo of herself channelling Marilyn Monroe alongside Meester, who was impersonating Aubrey Hepburn. The picture is from the fifth season, when they filmed a dreamscape scene set to Monroe’s hit “Diamonds Are a Girl’s Best Friend.”

And she also shared a sweet photo alongside her real-life ex Badgley in their cotillion wear for the 2007 episode “Hi, Society.” The pair dated during the filming of the series from 2007 to 2010.

Badgley, Crawford, Westwick and more costars were featured in the post.

Lively also shared a special photo of the late Michelle Trachtenberg, who died at the age of 39 in February and played Serena’s frenemy Georgina Sparks on the show.

“She was electricity. You knew when she entered a room because the vibration changed. Everything she did, she did 200%,” Lively said in a tribute to Trachtenberg, which she posted after her tragic death.

She continued: “She laughed the fullest at someone’s joke, she faced authority head on when she felt something was wrong, she cared deeply about her work, she was proud to be a part of this community and industry as painful as it could be sometimes, she was fiercely loyal to her friends and brave for those she loved, she was big and bold and distinctly herself.”

Lively recently reunited with another Gossip Girl costar, starring in an ad campaign for her Betty Booze Vodka Iced Teas alongside Zuzanna Szadkowski, who played Blair Waldorf (Meester)’s beloved maid Dorota.

After Gossip Girl ended its run, Lively remained a fixture in Hollywood. She went on to star in hit films such as A Simple Favor and it’s 2025 sequel Another Simple Favor, It Ends with Us, The Age of Adaline, The Shallows and making a cameo alongside husband Ryan Reynolds in 2024’s Deadpool & Wolverine.

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She also notably maintains a close connection with her costars  America Ferrera, Alexis Bledel and Amber Tamblyn from 2005’s The Sisterhood of the Traveling Pants.