The Cosby Show is an American television sitcom created by (along with Ed. Weinberger and Michael J. Leeson) and starring Bill Cosby that originally aired on NBC from September 20, 1984, to April 30, 1992, with a total of 201 half-hour episodes spanning eight seasons, including an outtakes special. The show focuses on the Huxtables, an upper middle-class Black-American family living in Brooklyn, New York; the series was based on comedy routines in Cosby's stand-up comedy act, which in turn were based on his family life. The series was followed by a spin-off, titled A Different World, which ran from September 24, 1987 to July 9, 1993, with a total of six seasons consisting of 144 episodes.

TV Guide listed the series as "TV's biggest hit in the 1980s", adding it "almost single-handedly revived the sitcom genre and NBC's ratings fortunes", while also ranking it 28th on their list of 50 Greatest Shows; with this list, Cliff Huxtable was named as the "Greatest Television Dad" in 2014. In May 1992, Entertainment Weekly stated that The Cosby Show helped to make possible a larger variety of shows with a predominantly black cast, from In Living Color to The Fresh Prince of Bel-Air.

The Cosby Show spent five consecutive seasons as the number-one rated show on television and, along with All in the Family, is the only sitcom in the history of the Nielsen ratings as the number-one show for five seasons, having spent the series in the top 20 ratings. It also remains the only scripted TV show with a predominantly African-American cast to top the Nielsen ratings, and to do so more than once. Its spinoff, A Different World, also became a ratings hit, featuring in the top 5 of the ratings for four of its six seasons. It launched the extended cast into stardom and Cosby, having already had a successful career on TV, films and stand-up, became the highest paid actor on television.

It was also an international hit, garnering a following from across the world being a regular fixture in markets previously considered unattainable for African-American leads, such as Europe, where the show became a ratings and commercial hit and cemented itself as an international icon of 1980s pop culture. Its effects on Black American portrayal and gender politics on television were a major part of its success. The portrayal of Clair Huxtable, the matriarch of the Huxtable family, by Phylicia Rashad sparked an international wave of working mothers on television dubbed the "Clair Huxtable effect", and Bill Cosby was nicknamed "America's Dad" for his highly celebrated portrayal of Cliff Huxtable. The colourful sweaters he wore as Cliff became a fashion trend for a time which was temporarily revived in the early 2010s. Another sitcom starring Cosby and Rashad, Cosby, aired on CBS from 1996 to 2000, notable for its differences to The Cosby Show, garnering positive reviews. Since 2014, reruns of The Cosby Show have been pulled from several networks and venues as a result of the Bill Cosby sexual assault cases.