Trachtenberg starred as the cunning Georgina Sparks on the beloved CW series, appearing in each of the six seasons and reprising her role in the recent reboot.

Michelle Trachtenberg's co-stars and fellow celebrities are speaking out after the "Gossip Girl" and "Harriet the Spy" star was found dead Wednesday.

Michelle Trachtenberg, an American actor known for her roles in the television series "Buffy the Vampire Slayer" and "Gossip Girl," died on Wednesday, according to her public relations team. "It is with great sadness to confirm that Michelle Trachtenberg has passed away.

Michelle Trachtenberg, star of “Buffy the Vampire Slayer” and “Harriet the Spy,” has passed away at age 39, according to the New York Police Department. The cause of death was not immediately disclosed,

Actress Michelle Trachtenberg, known for her role in "Gossip Girl," was found dead in a New York City luxury apartment building by the NYPD. She was 39.

Blake Lively took to her Instagram Stories Wednesday evening to share a lengthy tribute to her “Gossip Girl” costar Michelle Trachtenberg. “This is the first day I met Michelle,” Lively wrote, sharing a photo of her and Trachtenberg on “Gossip Girl.