Blake Lively Marks 18 Years Since 'Gossip Girl' with Heartfelt Throwback Photos

Blake Lively is celebrating the 18th anniversary of "Gossip Girl" with a nostalgic tribute and never-before-seen throwback photos with the rest of the cast and crew.

Blake Lively is reminiscing about a defining chapter in her career, one that marked her teenage years with good memories and unmeasurable learning experiences.

On Sunday, September 21, 2025, the actress marked the 18th anniversary of "Gossip Girl," the hit teen drama that premiered in 2007. Sharing a series of photos from the set on Instagram, Lively, 38, reflected on what the show meant to her.

"The summer gossip girl turned 18…," she wrote, before describing the experience as formative both personally and professionally.

"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," Lively added. "So many memories. What. A. Decade. 💖 What a University."

The post included a group photo of the cast along with behind-the-scenes moments featuring Leighton Meester, Ed Westwick, and Penn Badgley.

Based on Cecily von Ziegesar’s bestselling book series, "Gossip Girl" ran on The CW from September 2007 to December 2012. Lively starred as Serena van der Woodsen, the glamorous New York socialite at the center of the story.