Gellar was born in New York City, the only child of Rosellen (née Greenfield), a nursery school teacher, and Arthur Gellar, a garment worker.^[3] Both of her parents were Jewish, though Gellar’s family had a Christmas tree during the holidays while she was growing up.^[4][5] In 1984, her parents divorced and she was brought up by her mother on the Upper East Side.

Gellar was estranged from her father from this time until his death from liver cancer on October 9, 2001. She attended New York’s Columbia Grammar & Preparatory School on a scholarship, and the Professional Children’s School. Gellar held a straight-A average and became a competent figure skater. Her best friend was Melissa Joan Hart, who later was the star of the series Sabrina, the Teenage Witch. She also became close friends with Lindsay Sloane, who (in September 2002) would be her bridesmaid at her wedding.

At the age of four, Gellar was spotted by an agent in a restaurant in Uptown Manhattan. Two weeks later, she auditioned for a part in An Invasion Of Privacy, a made-for-television film starring Valerie Harper, Carol Kane and Jeff Daniels. At the audition, Gellar read both her own lines and those of Harper, impressing the directors enough to cast her in the role. A short while later, she got a part in a controversial television commercial for Burger King, in which she criticized McDonald’s and claimed to eat only at Burger King.

This led to a lawsuit by McDonalds against Burger King, ad agency J. Walter Thompson, and child-actress Gellar herself, who appeared in court as a witness for the defense. The dispute was eventually settled out of court.^[6] Gellar continued to make commercials while appearing in acting roles, including playing Emily in an episode of the TV series Spenser: For Hire, appearing in a minor role in the Chevy Chase starring comedy Funny Farm and in the movie High Stakes, and filming in Europe for the TV series Crossbow. In 1991, she played a young Jacqueline Bouvier in A Woman Named Jackie.

Gellar got her first major break in 1992, when she starred in the serial Swans Crossing and was subsequently cast in the soap opera All My Children, playing Kendall Hart, the long-lost daughter of character Erica Kane (Susan Lucci). In 1995, at the age of eighteen, she won a Daytime Emmy Award for Outstanding Younger Leading Actress in a Drama Series for the role.^[7] It was on the set of this soap opera that she met Michelle Trachtenberg who would later join the Buffy the Vampire Slayer cast.

In 2000, Gellar guest starred as Debbie in the HBO series Sex and the City episode Escape from New York. Sarah Michelle Gellar has also hosted Saturday Night Live a total of three times (1998, 1999, and 2002). Gellar has lent her voice to animated TV series, The Simpsons, King of the Hill, and several episodes of Robot Chicken.

Gellar left All My Children in 1995 amid rumors of a strained working relationship with Lucci. Gellar stated that she was screen tested eleven times (originally auditioning for the role of Cordelia), before she landed the lead in the 1997 TV series Buffy the Vampire Slayer, playing a teenager burdened with the responsibility of fighting a number of mystical foes, mostly vampires. The show was well received by critics and audiences alike, spawning a spin-off series (Angel), which featured two episodes in which she notably guest starred. Throughout its seven seasons and a total of 144 episodes, Buffy, and by extension Gellar, became cult icons in the United States, the UK and Australia, particularly as archetypes of “empowered” women.^[8] Gellar sang several of the songs during the Buffy the Vampire Slayer musical episode “Once More, with Feeling“, which spawned an original cast album.

During the show’s later years, Gellar expressed dissatisfaction about certain aspects of the show.^[9] Shortly after the show’s end, Gellar stated that she had no interest in appearing in a Buffy feature film, although since then she has said she will consider it if the script is good enough.^[10] She did not appear in the final season of Angel, causing the intended episode (”You’re Welcome“) to be rewritten for the character of Cordelia Chase.^[11] Gellar has said that she was willing to appear in the episode, but scheduling conflicts and family problems prevented it.^[12] Gellar has declined to lend her voice to the various Buffy video games, and another actress voiced Buffy for an animated series based on the show, which never aired.

In her feature in Esquire magazine Gellar expressed her pride for her work on Buffy, “I truly believe that it is one of the greatest shows of all time and it will go down in history as that. And I don’t feel that that is a cocky statement. We changed the way that people looked at television.”^[13]

Gellar’s likeness is used in the comic continuation of the series.It was reported on September 25, 2008 that Gellar would return to television in the HBO series The Wonderful Maladys.^[14][15] The show is about three dysfunctional adult siblings living in New York and struggling to deal with the loss of their parents years ago.^[16] Creator Charles Randolph told Variety that he wrote the part with Gellar in mind,^[16] and described Gellar’s character as having “a kind of zealous immaturity – like a drug addict with a to-do list.”^[16] HBO plans to shoot the pilot (using a single camera) in early 2009.^[17][18] Gellar and Randolph will serve as executive producers.^[19]