Michelle Trachtenberg dead at 39: Rosie O’Donnell, Ed Westwick and more former co-stars react

Ed Westwick, Rosie O’Donnell, David Boreanaz and more stars are paying tribute to Michelle Trachtenberg.

Following the heartbreaking news that the “Buffy the Vampire Slayer” and “Gossip Girl” star died Wednesday at the age of 39, her former co-stars took to social media to honor the late actress. 

Westwick –– who played Chuck Bass in The CW’s “Gossip Girl” –– mourned Trachtenberg’s death by sharing a photo of her as her Georgina Sparks character.

Michelle Trachtenberg’s co-stars took to social media to mourn her death. WWD via Getty Images Ed Westwick, who starred in “Gossip Girl” with Trachtenberg, posted an Instagram Story on Wednesday. Instagram/edwestwick

“So sad to hear of the passing of @michelletrachtenberg sending prayers 🙏🏻🤍,” he wrote on his Instagram Story Wednesday.

Boreanaz, who starred on “Buffy the Vampire Slayer” in its first three seasons, posted her death announcement to his Instagram Story and wrote, “So very sad …horrible news. RIP and prayers to her and her family.”

O’Donnell, who co-starred in “Harriet the Spy” with Trachtenberg told Us Weekly, “Heartbreaking. I loved her very much. She struggled the last few years. I wish I could have helped.”

David Boreanaz, who also starred in “Buffy the Vampire Slayer” before Trachtenberg joined the series, called the news “horrible.” Instagram/imdboreanz Rosie O’Donnell, who starred in “Harriet the Spy” alongside Trachtenberg, mourned her death as well. Paramount/Kobal/Shutterstock

Sources told The Post that Trachtenberg’s mother found her “unconscious and unresponsive” around 8 a.m. in her New York City apartment near Columbus Circle.

The former Nickelodeon star’s cause of death has not been revealed, but insiders told The Post that the death is not being investigated as suspicious.

Page Six has reached out to the New York coroner’s office and Michelle’s rep for comment.

Trachtenberg starred in “Gossip Girl” with Jessica Szohr, Leighton Meester and Penn Badgley. WireImage The late actress also worked with Sarah Michelle Gellar on “Buffy the Vampire Slayer.” Seth Green — seen above with Gellar and Trachtenberg — left the series before the latter joined the show. FilmMagic

Trachtenberg died after recently undergoing a liver transplant that may have led to complications, sources told The Post.

The “Buffy” actress previously raised concerns over her physical appearance on her Instagram, but she also clapped back at fans who expressed those worries.

After some fans commented that she looked “sick” under a January 2024 Instagram post, she replied, “Explain to me how I look sick. Did you lose a calendar and not realize I’m not 14. I’m 38. How sad for you to leave such a comment.”

Trachtenberg doubled down on her sentiment by sharing another selfie the next day and assured fans that she was “happy and healthy.”

Trachtenberg’s mom found her dead in her New York City apartment Wednesday morning. Michelle Trachtenberg/Instagram

The “Ice Princess” actress’ last photo that she shared on Instagram before her death was a selfie outside.

Trachtenberg was born and raised in New York City and took up acting when she was just three. She scored her first major gig on the Nickelodeon show “The Adventures of Pete & Pete” in 1991.

She went on to star in a slew of other beloved TV shows and movies –– including “17 Again,” “EuroTrip” and “Inspector Gadget.”