Situation comedies, or sitcoms, have long been a popular genre of comedy in the US, initially on radio in the 1920s, and then on television beginning in the 1940s. A sitcom is defined as a television series featuring a recurring cast of characters in various successive comedic situations.

The first sitcom was the radio show Sam 'n' Henry, which had evolved into Amos 'n' Andy by 1928. Mary Kay and Johnny, the first American TV sitcom, premiered in 1947, and by the 1950s, I Love Lucy was leading TV viewership. Since that time, sitcoms such as The Beverly Hillbillies, Bewitched, All in the Family, Cheers, The Cosby Show, Seinfeld, and Friends have each been the highest annual rated TV series in the US for at least one season.

Radio

The sitcom format was born in January 1926 with the initial broadcast of Sam 'n' Henry on WGN radio in Chicago, Illinois. The 15-minute daily program was revamped in 1928, moved to another station, renamed Amos 'n' Andy, and became one of the most successful sitcoms of the period. It was also one of the earliest examples of radio syndication. Like many radio programs of the time, the two programs continued the American entertainment traditions of vaudeville and the minstrel show. Early sitcoms took the forms of recurring comedy sketches with running characters, which on national network shows often took the form of a broader variety show with vocal and instrumental music performances padding out a half-hour time slot.

The Jack Benny Program, a radio-TV comedy series that ran for more than three decades, is generally regarded as a high-water mark in 20th-century American comedy.

Fibber McGee and Molly was one of radio's most popular sitcoms of the 1940s. The weekly half-hour domestic sitcom starring real-life husband and wife Jim Jordan and Marian Driscoll ran from 1935 to 1956 on NBC.

Television

1940s Mary Kay and Johnny, aired from 1947 to 1950, was the first sitcom broadcast on network television in the United States and was the first program to show a couple sharing a bed, and the first series to show a woman's pregnancy on television. The Goldbergs ran for six seasons on CBS and NBC from 1949 to 1954 before airing on sydication.

1950s

I Love Lucy, which originally ran from 1951 to 1957 on CBS, was the most watched show in the United States in four of its six seasons, and was the first to end its run at the top of the Nielsen ratings (an accomplishment later matched only by The Andy Griffith Show in 1968 and Seinfeld in 1998). The show is still syndicated in dozens of languages across the world, and remains popular with an American audience of 40 million each year. Colourised edits of episodes from the original series have aired semi-annually on the network since 2013, six decades after the series aired. It is often regarded as one of the greatest and most influential sitcoms in history. In 2012, it was voted the 'Best TV Show of All Time' in a survey conducted by ABC News and People Magazine.

The Honeymooners debuted as a half-hour series on 1955 and was originally aired on the DuMont network's Cavalcade of Stars and subsequently on the CBS network's The Jackie Gleason Show, which was filmed in front of a live audience. Although initially a ratings success—becoming the No. 2 show in the United States during its first season—it faced stiff competition from The Perry Como Show, and eventually dropped to No. 19,Brooks; Marsh, "Top-Rated Programs by Season", p.1245 ending its production after only 39 episodes (now referred to as the "Classic 39"). The final episode of The Honeymooners aired on September 22, 1956. Creator/producer Jackie Gleason revived The Honeymooners sporadically until 1978. The Honeymooners was one of the first U.S. television shows to portray working class married couples in a gritty, non-idyllic manner (the show is set mostly in the Kramdens' kitchen, in a neglected Brooklyn apartment building).Conner (2010), Sitcoms Often Reinforce Racial Ethnic Stereotypes Steven Sheehan explains the popularity of The Honeymooners as the embodiment of working-class masculinity in the character of Ralph Kramden, and postwar ideals in American society regarding work, housing, consumerism, and consumer satisfaction. The series demonstrated visually the burdens of material obligations and participation in consumer culture, as well as the common use of threats of domestic violence in working class households.Steven T. Sheehan, "'Pow! Right in the Kisser': Ralph Kramden, Jackie Gleason, and the Emergence of the Frustrated Working-Class Man, Journal of Popular Culture, June 2010, Vol. 43#3 pgs. 564-82 Art Carney won five Emmy Awards for his portrayal of Ed Norton — two for the original Jackie Gleason Show, one for The Honeymooners, and two for the final version of The Jackie Gleason Show. He was nominated for another two (1957, 1966) but lost. Gleason and Audrey Meadows were both nominated in 1956 for their work on The Honeymooners. Meadows was also nominated for Emmys for her portrayal of Alice Kramden in 1954 and 1957. In 1997, the episodes "The $99,000 Answer" and "TV or Not TV" were respectively ranked No. 6 and No. 26 on "TV Guide's 100 Greatest Episodes of All Time" and in 1999, TV Guide published a list titled "TV's 100 Greatest Characters Ever!" Ed Norton was No. 20, and Ralph Kramden was No. 2. In 2002, The Honeymooners was listed at No. 3 on TV Guide's 50 Greatest TV Shows of All Time and No. 13 on their list of the "60 Greatest Shows of All Time" in 2013.

1960s The Andy Griffith Show, first televised on CBS between 1960 and 1968, was consistently placed in the top ten during its run. The show is one of only three shows to have its final season be the number one ranked show on television, the other two being I Love Lucy and Seinfeld. In 1998, more than 5 million people a day watched the show's re-runs on 120 stations.

The Dick Van Dyke Show, initially aired on CBS from 1961 to 1966, won 15 Emmy Awards. In 1997, the episodes "Coast-to-Coast Big Mouth" and "It May Look Like a Walnut" were ranked at 8 and 15 respectively on TV Guide's 100 Greatest Episodes of All Time. In 2002, it was ranked at 13 on TV Guide's 50 Greatest TV Shows of All Time and in 2013, it was ranked at 20 on their list of the 60 Best Series.

1970s

The Mary Tyler Moore Show ran from 1970 to 1977, winning 29 Emmy Awards. MTM Enterprises, the studio formed to produce it, would produce dozens of sitcoms from the 1970s through the 1990s.

The series M*A*S*H, aired in the U.S. from 1972 to 1983, and was honoured with a Peabody Award in 1976 and was ranked number 25 on TV Guide's 50 Greatest TV Shows of All Time in 2002. In 2013, the Writers Guild of America ranked it as the fifth-best written TV series ever and TV Guide ranked it as the eighth-greatest show of all time. The episodes "Abyssinia, Henry" and "The Interview" were ranked number 20 and number 80, respectively, on TV Guide's 100 Greatest Episodes of All Time in 1997. And the finale, "Goodbye, Farewell and Amen", became the most-watched and highest-rated single television episode in the U.S. television history at the time, with a record-breaking of 125 million viewers (60.2 rating and 77 share), according to The New York Times.

Sanford and Son, which ran from 1972 to 1977, was included on the Time magazine's list of the "100 Best TV Shows of All Time" in 2007.

All in the Family, premiered in January 1971, is often regarded in the United States as one of the greatest television series of all time. Following a lackluster first season, the show became the most watched show in the United States during summer re-runs and afterwards ranked number one in the yearly Nielsen ratings from 1971 to 1976. It became the first television series to reach the milestone of having topped the Nielsen ratings for five consecutive years. The episode "Sammy's Visit" was ranked number 13 on TV Guide's 100 Greatest Episodes of All Time. TV Guide's 50 Greatest TV Shows of All Time ranked All in the Family as number four. Bravo also named the show's protagonist, Archie Bunker, TV's greatest character of all time. In 2013, the Writers Guild of America ranked All in the Family the fourth-best written TV series ever, and TV Guide ranked it as the fourth-greatest show of all time.

One Day at a Time is a situation comedy developed by Norman Lear. The show aired on CBS and ran from December, 1975 until May, 1984. It followed a recently divorced mother and her two daughters as they dealt with the problems and situations that come with growing up, and raising kids in a single parent household. It is the first show to feature Valerie Bertinelli, and emphasized her character as the show progressed.

1980s Cheers, which ran for eleven seasons, was one of the most successful sitcoms in the 80s, airing from 1982 to 1993. It was followed by a spin-off sitcom in the 90s, Frasier. During its run, Cheers became one of the most popular series of all time and has received critical acclaim. In 1997, the episodes "Thanksgiving Orphans" and "Home Is the Sailor", aired originally in 1987, were respectively ranked No. 7 and No. 45 on TV Guide's 100 Greatest Episodes of All-Time. In 2002, Cheers was ranked No. 18 on TV Guide's 50 Greatest TV Shows of All Time. In 2013, the Writers Guild of America ranked it as the eighth best written TV series and TV Guide ranked it No. 11 on their list of the 60 Greatest Shows of All Time.

The Cosby Show, airing from 1984 until 1992, spent five consecutive seasons as the number one rated show on television. The Cosby Show and All in the Family are the only sitcoms in the history of the Nielsen ratings to be the number one show for five seasons. It spent all eight of its seasons in the Top 20. According to TV Guide, the show "was TV's biggest hit in the 1980s, and almost single handedly revived the sitcom genre and NBC's ratings fortunes." TV Guide also ranked it 28th on their list of 50 Greatest Shows. In addition, Cliff Huxtable was named as the "Greatest Television Dad". In May 1992, Entertainment Weekly stated that The Cosby Show helped to make possible a larger variety of sitcoms with a predominantly African-American cast, such as its direct spin-off A Different World, and from another studio The Fresh Prince of Bel-Air.

Mama's Family originally aired on NBC, debuting on January 22, 1983. After two seasons, the show was canceled in 1984 and subsequently revived for an additional four seasons in September 1986 until February 1990.

The Golden Girls originally aired on NBC from September 14, 1985, to May 9, 1992, with a total of 180 half-hour episodes, spanning seven seasons. The show received critical acclaim throughout most of its run, and won several awards, including the Primetime Emmy Award for Outstanding Comedy Series twice. It also won three Golden Globe Awards for Best Television Series – Musical or Comedy.

Another popular sitcom from this decade was Roseanne, which ran from 1988 to 1997.

1990s