Buffy the Vampire Slayer is an American supernatural drama television series created by writer and director Joss Whedon. The concept is based on the 1992 film, also written by Whedon, although they are separate and unrelated productions. Whedon served as executive producer and showrunner of the series under his production tag Mutant Enemy Productions. It premiered on March 10, 1997, on The WB and concluded on May 20, 2003, on UPN.

The series follows Buffy Summers (played by Sarah Michelle Gellar), the latest in a succession of young women known as "Vampire Slayers". Slayers are chosen by fate to battle against vampires, demons and other forces of darkness. Buffy wants to live a normal life, but learns to embrace her destiny as the series progresses. Like previous Slayers, she is aided by a Watcher, who guides, teaches and trains her. Unlike her predecessors, Buffy surrounds herself with loyal friends who become known as the "Scoobies". The show primarily takes place in the fictional setting of Sunnydale, a small Southern California city located on a "Hellmouth"; a portal "between this reality and the next", and a convergence point of mystical energies. Because of this, supernatural creatures and beings with magical powers, both good and evil, are drawn to Sunnydale or rise from below ground to menace the town and the world.

The series received critical and popular acclaim, and is often listed among the greatest television series of all time. Original airings often reached four to six million viewers. Although lower than successful shows on the "big four" networks (ABC, CBS, NBC and Fox), these ratings were a success for the relatively new and smaller WB Television Network. Despite being mostly ignored in above-the-line categories by the Emmys, the series was nominated for the American Film Institute Award for Drama Series of the Year, Gellar was nominated for the Golden Globe Award for Best Actress – Television Series Drama for her performance in the show and the series was nominated five times for Television Critics Association Awards, winning in 2003 for the Television Critics Association Heritage Award.

The success of Buffy has led to hundreds of tie-in products, including novels, comics and video games. The series has received attention in fandom (including fan films), parody, and academia, and has influenced the direction of other television series. Buffy was part of a wave of television series from the late 1990s and early 2000s that featured strong female characters, alongside Charmed, Xena: Warrior Princess, La Femme Nikita, Dark Angel, and Alias. The series, as well as its spin-off series, Angel, and extensions thereof, have been collectively termed the "Buffyverse".