1988–2003

Trachtenberg made her first television appearance at the age of three, in a commercial for Wisk detergent.^[8] She went on to feature in over 100 more commercials.^[8] Her first television role was in the second season of Law & Order; her first credited role was as Nona F. Mecklenberg on the Nickelodeon series The Adventures of Pete & Pete from 1994 until 1996. During the same period she played Lily Montgomery on the soap opera All My Children.^[9][10]

Trachtenberg's film career began in 1996 with the title role in Harriet the Spy, for which she had to leave The Adventures of Pete & Pete while its third season was running.^[11] She then starred in the short-lived television series Meego, which garnered her a Young Artist Award.^[12] She returned to film in 1999 for Inspector Gadget. She also starred in the film Can't Be Heaven. In the summer of 2000, she took on the role of Dawn Summers in Buffy the Vampire Slayer, remaining in the role until the show ended in 2003. She also hosted the Discovery Kids series Truth or Scare from 2001 to 2003.

2004–2007

After Buffy and Truth or Scare, Trachtenberg appeared in the comedy film EuroTrip. She also had a recurring role in the HBO series Six Feet Under, as Celeste, a spoiled pop star for whom Keith Charles served as a bodyguard. In March 2005, she starred in Walt Disney Pictures' comedy sports drama film Ice Princess as Casey Carlyle, a science whiz, who is torn between a future in academia and her newfound dream of being a professional figure skater.

In 2004, Trachtenberg played Wendy in Gregg Araki's film adaptation of Scott Heim's novel, Mysterious Skin. Wendy is the best friend of Neil (Joseph Gordon Levitt), a teenage hustler in small-town Kansas. The film debuted at the 2004 Venice Film Festival.

In April 2006, Trachtenberg guest-starred in the episode of House, "Safe". She revealed on the December 22, 2006, episode of Late Night with Conan O'Brien that House was her favorite show, and that she was friends with one of the producers and had asked to be a guest star.^[13]

In November 2006, Trachtenberg guest starred in season six of the crime drama Law & Order: Criminal Intent. In the episode "Weeping Willow", she played the role of Willow, a kidnapped video blogger, likely based on lonelygirl15.^[14] Trachtenberg also appeared in the Fall Out Boy music video for "This Ain't a Scene, It's an Arms Race", the Joaquin Phoenix-directed music video for "Tired of Being Sorry" by Ringside, and the video for the Trapt song "Echo".

In 2006, Trachtenberg starred in Black Christmas, the remake of the 1974 slasher of the same name. In 2007, she was cast as the female lead in an ABC comedy pilot called The Hill, based on the newspaper of the same name in Washington, D.C.^[15]

2008–2010

Trachtenberg provided the voice of Tika Waylan for Dragonlance: Dragons of Autumn Twilight, a direct-to-video animated film based on the novel of the same name.^[16] She appeared on The CW hit show Gossip Girl, as Georgina Sparks, who recently left rehab and brings back the dark past Serena van der Woodsen desperately wants to leave behind.^[17] She returned to the show for a multiple-episode story arc towards the end of season two.^[18] Trachtenberg appeared in the season-three finale and in season four. She also appeared several times in season five, and in almost every episode of season six, the show's final season.^[19] In 2009, Trachtenberg was a cast member on the NBC drama series Mercy, which lasted one season.^[20] She then returned to film, starring in the 2009 teen fantasy comedy 17 Again, and had a small role in the comedy Cop Out (2010).^[21]

2011–present

On June 9, 2011, Trachtenberg guest starred on Love Bites, as Jodie, who, after being unceremoniously dumped, decides – with a vengeance – to accept her ex's offer to "be friends". She reprised the role on June 16, 2011, and in the series finale on July 21, 2011. In the same year, Trachtenberg was a guest star on Weeds during its seventh season,^[22] portraying Emma, a rival pot dealer who causes problems for Silas Botwin. In June 2012, Trachtenberg was cast in the film The Scribbler, produced by Gabriel Cowan.^[23]

In the Criminal Minds episode "Zugzwang", Trachtenberg played Diane Turner, the criminal stalker to Spencer Reid's girlfriend, Maeve Donovan. In March 2011, she was the featured cover girl in Maxim.^[24]

In late 2015, Trachtenberg starred in the online series Guidance as Anna, the high school guidance counselor.^[25]

Film

Television

Web series

Music videos