Buffy the Vampire Slayer is an Emmy and Golden Globe-nominated American cult television series that initially aired from March 10, 1997 until May 20, 2003. It was created by writer-director Joss Whedon under his production tag, Mutant Enemy. The series narrative follows Buffy Anne Summers (played by Sarah Michelle Gellar), the latest in a line of young women chosen by fate to battle against vampires, demons, and the forces of darkness. Like previous slayers, Buffy is aided by a Watcher, who guides and trains her. Unlike her predecessors, Buffy surrounds herself with a circle of loyal friends who become known as the "Scooby Gang."

The series usually reached between four and six million viewers on original airings. Although such ratings are lower than successful shows on the "big four" networks (ABC, NBC, CBS and Fox), they were a success for the relatively new and smaller The WB Television Network. Reviews for the show were overwhelmingly positive, and it was ranked #41 on the list of TV Guide's 50 Greatest TV Shows of All Time. The WB network ceased operation on September 17, 2006 after airing an "homage" to their "most memorable series", including the pilot episodes of Buffy and its spin-off, Angel.

Buffy's success has led to hundreds of tie-in products, including novels, comics, and video games. The series has received attention in fandom, parody, and academia, and has influenced the direction of other television series.

Writer Joss Whedon says that "Rhonda the Immortal Waitress was really the first incarnation of [the Buffy concept], just the idea of some woman who seems to be completely insignificant who turns out to be extraordinary." Whedon developed Buffy to invert the Hollywood formula of "the little blonde girl who goes into a dark alley and gets killed in every horror movie." Whedon wanted "to subvert that idea and create someone who was a hero." He explained: "The very first mission statement of the show [is] the joy of female power: having it, using it, sharing it."

Buffy, the Chosen One, falls in love with Angel, a vampire.The concept was first visited through Whedon's script for the 1992 movie Buffy the Vampire Slayer, which featured Kristy Swanson in the title role. The director, Fran Rubel Kuzui, saw it as a "pop culture comedy about what people think about vampires." Whedon disagreed: "I had written this scary film about an empowered woman, and they turned it into a broad comedy. It was crushing." The script was praised within the industry, but the movie was not.

Several years later, Gail Berman, a Sandollar Productions executive, approached Whedon to develop his Buffy concept into a television series. Whedon explained that "They said, 'Do you want to do a show?' And I thought, 'High school as a horror movie.' And so the metaphor became the central concept behind Buffy, and that's how I sold it." The supernatural elements in the series stood as metaphors for personal anxieties associated with adolescence and young adulthood. Whedon went on to write and partly fund a 25-minute unaired Buffy pilot that was shown to networks and eventually sold to the WB Network. The latter promoted the premiere with a series of History of the Slayer clips, and the first episode aired on March 10, 1997.

The title role went to Sarah Michelle Gellar, who had appeared as Sydney Rutledge in Swans Crossing and Kendall Hart in All My Children. At age eighteen in 1995, Gellar had already won a Daytime Emmy Award for Outstanding Younger Leading Actress in a Drama Series. In 1996, she was initially cast as Cordelia Chase during a week of auditioning.

Anthony Stewart Head had already led a prolific acting and singing career but remained best known for a series of twelve coffee commercials with Sharon Maughan for Nescafé Gold Blend. He accepted the role of Rupert Giles.

Unlike other Buffy regulars, Nicholas Brendon had little acting experience, instead working various jobs — including production assistant, plumber's assistant, veterinary janitor, food delivery, script delivery, day care counselor and waiter — before deciding to break into acting to help him overcome a stutter. He landed his Xander Harris role following only four days of auditioning.
 

The first season exemplifies the "high school as hell" concept. Buffy Summers has just moved to Sunnydale and hopes to escape her Slayer duties. Her plans are complicated by Rupert Giles, her new Watcher, who reminds her of the inescapable presence of evil. Sunnydale High is built atop a Hellmouth, a portal to demon dimensions that attracts supernatural phenomena to the area. Buffy meets two schoolmates who will help fight evil through the series, but they must first prevent an ancient and especially threatening vampire from opening the Hellmouth and unleashing Hell on Earth.

The emotional stakes are raised in the second season. New vampires, Spike and a weakened Drusilla, come to town along with the new Slayer, who was activated as a result of Buffy's brief death in the first season finale. Buffy consummates her relationship with her vampire lover Angel, and consequentially, she unwittingly removes his cursed soul as a result. He once more becomes a sadistic killer seeking to destroy the world. Buffy is forced to kill him, and leaves Sunnydale, emotionally shattered.

After attempting to start a new life in Los Angeles, Buffy returns to town in the third season. She is soon confronted with an unstable Slayer, Angel (again), and an often affable but definitely evil mayor's plans for Graduation Day.

The fourth season sees Buffy and Willow enroll at UC Sunnydale while Xander joins the workforce. Willow falls in love with another witch, while Buffy begins dating a student who is a member of The Initiative, a top-secret military installation based beneath the UC Sunnydale campus. They appear to be a well-meaning anti-demon operation, but a secret project goes horribly wrong. The season also marked the first year in which Joss Whedon oversaw other TV series.

During the fifth season, an exiled Hell-God searches for a "key" that will allow her to return to her home dimension. The "key" has been turned into human form as Buffy's younger sister Dawn. The Hell-God eventually discovers the truth and kidnaps Dawn; Buffy sacrifices herself to save Dawn and the world.

Buffy's friends resurrect her through a powerful spell in the sixth season. Buffy returns from Heaven and finds a job at a fast food restaurant. Her friends are unaware of her inner turmoils as they face their own troubles: Xander leaves his fiancée at the altar, and Willow becomes addicted to magic. When Willow's girlfriend is killed by a deranged murderer, Willow descends into darkness and begins a rampage that nearly causes the end of the world.

The instability caused by Buffy's revival enables the First Evil to amass an army of powerful vampires against humankind during the seventh season, in the process trying to kill every currently-unactivated Potential Slayer. Willow invokes a spell that activates all the "Potentials" in the world as the Scooby Gang defeats evil once more.