"It is with great sadness to confirm that Michelle Trachtenberg has passed away. The family requests privacy for their loss. There are no further details at this time," a statement from her public relations team said.
The cause of her death on Wednesday was not known.
The actor was born on October 11 in 1985 in New York City to Jewish immigrant parents.
As a child, Trachtenberg got her start in Hollywood when she was three years old in commercials and her television debut was in the Nickelodeon series The Adventures of Pete & Pete in 1994.
At 10 years of age, she landed her first title role in the 1996 movie Harriet the Spy.
She had roles in several Nickelodeon productions leading up to her being cast in the cult classic EuroTrip in 2004 when she was in her early twenties.
Then came the roles that she is best known for, including the character Dawn Summers in the WB supernatural drama Buffy the Vampire Slayer in 2000 and as Georgina Sparks on the CW television series Gossip Girl in 2007.
Some of her other roles include TV films Killing Kennedy, Sister Cities and the science fiction film The Scribbler.
Trachtenberg also appeared in music videos from emo-rock band Fall Out Boy for their song This Ain't a Scene, It's an Arms Race, and the Joaquin Phoenix-directed music video for Tired of Being Sorry by Ringside.
