A talk show or chat show is a television programming or radio programming genre in which one person (or group of people) discusses various topics put forth by a talk show host.^[1]

Usually, guests consist of a group of people who are learned (such as current affairs experts or pundits) or who have experience with whatever issue is being discussed on the show for that episode. Other times, a single guest such as a celebrity or expert discusses their work or area of expertise with a host or co-hosts. A call-in show takes live phone calls from callers listening at home, in their cars, in their gardens, etc. Sometimes, guests are already seated but are often introduced and enter from backstage. There have been many notable talk show hosts; in many cases, the shows have made their hosts famous.

There are several major formats of talk shows.

Generally, each subgenre predominates during a specific programming block during the broadcast day.

These formats are not absolute.

Syndicated "daytime" shows may appear overnight in some markets, and some afternoon programs have similar structures to late night talk shows.

These formats may vary across different countries or markets.

Late night talk shows are especially significant in the United States. Breakfast television is a staple of British television. The daytime talk format has become popular in Latin America as well as the United States.

Talk-radio host Howard Stern also hosted a talk show that was syndicated nationally in the USA, then moved to satellite radio's Sirius. The tabloid talk show genre, pioneered by Phil Donahue^[2] but popularized by Oprah Winfrey^[3] was extremely popular during the last two decades of the 20th century.^[4]

Politics are hardly the only subject of American talk shows, however.

Other radio talk show subjects include Car Talk hosted by NPR and Coast to Coast AM hosted by Art Bell and George Noory which discusses topics of the paranormal, conspiracy theories, fringe science, and the just plain weird. Sports talk shows are also very popular ranging from high-budget shows like The Best Damn Sports Show Period to Max Kellerman's original public-access television cable TV show Max on Boxing.

Talk shows have been broadcast on television since the earliest days of the medium. Joe Franklin, an American radio and television personality, hosted the first television talk show. The show began in 1951 on WJZ-TV (later WABC-TV) and moved to WOR-TV (later WWOR-TV) from 1962 to 1993.^[5]

NBC's The Tonight Show is the world's longest-running talk show; having debuted in 1954, it continues to this day. The show underwent some minor title changes until settling on its current title in 1962, and despite a brief foray into a more news-style program in 1957 and then reverting that same year, it has remained a talk show. Ireland's The Late Late Show

Steve Allen was the first host of The Tonight Show, which began as a local New York show, being picked up by the NBC network in 1954. It in turn had evolved from his late-night radio talk show in Los Angeles. Allen pioneered the format of late night network TV talk shows, originating such talk show staples as an opening monologue, celebrity interviews, audience participation, and comedy bits in which cameras were taken outside the studio, as well as music, although the series' popularity was cemented by second host Jack Paar, who took over after Allen had left and the show had ceased to exist.

TV news pioneer Edward R. Murrow hosted a talk show entitled Small World in the late 1950s and since then, political TV talk shows have predominantly aired on Sunday mornings.

Syndicated daily talk shows began to gain more popularity during the mid-1970s and reached their height of popularity with the rise of the tabloid talk show. Morning talk shows gradually replaced earlier forms of programming — there were a plethora of morning game shows during the 1960s and early to mid-1970s, and some stations formerly showed a morning movie in the time slot that many talk shows now occupy.

Current late night talk shows such as and The Late Show with Stephen Colbert have aired featuring celebrity guests and comedy sketches. Syndicated daily talk shows range from tabloid talk shows, such as Jerry Springer and Maury to celebrity interview shows like Live with Kelly and Ryan, The Better Show, The Wendy Williams Show, and Ellen to industry leader The Oprah Winfrey Show which popularized the former genre and has been evolving towards the latter. On November 10, 2010, Oprah Winfrey invited several of the most prominent American talk show hosts - Phil Donahue, Sally Jessy Raphael, Geraldo Rivera, Ricki Lake, and Montel Williams - to join her as guests on her show. The 1990s in particular saw a spike in the number of "tabloid" talk shows, most of which were short-lived and are now replaced by a more universally appealing "interview" or "lifestyle TV" format.^[6]

Talk shows have more recently started to appear on Internet radio.

Also, several Internet blogs are in talk show format including the Baugh Experience.

The current world record for the longest talk show is held by Rabi Lamichhane from Nepal by staying on air for 62 hours from April 11 to 13, 2013 breaking the previous record set by two Ukrainians by airing the show for 52 hours in 2011.^[7]

Rabi Lamichhane from Nepal holds the present world record for longest ever talk show.

In Japan, panel shows — called "tooku bangumi" (トーク番組）in Japanese — are very commonplace, accounting for about 30% of daytime and prime-time programming on the four main television stations. Due to language and cultural differences, Japanese TV stations could not freely use syndicated programs (mostly from Europe and North America) and therefore turned to panel shows, which could be produced cheaply and easily, to fill time during daytime programming.

Japanese panel shows are distinct in generally not employing regular panelists but instead having a panel made up of different freelance comedians and celebrities each program, although the program is generally hosted by the same compere. Talk shows evolved in tandem with the Japanese variety show and it is very common for talk shows to borrow variety elements, typically by having celebrity guests attempt some kind of amusingly incongruous activity. Often, one of the guests will be a gaijin tarento (foreign talent) in order to provide comedy or to comment on matters related to Western culture. Comedic material is commonly written and rehearsed before tapings with or without a live audience.

Korean and Taiwanese talk shows have used the panel format similar to Japanese programs and rely on famous celebrities and comedic banter than topics.

Their programs often shorten interviews from lengthy tapings.

In Brazil, Jô Soares inaugurated the genre with Jô Soares Onze e Meia ("Jô Soares Eleven Thirty") from 1988 to 1999. In 2000, Soares took his show's format to Rede Globo, where it was then called Programa do Jô, and hosts the program until the present day. Jô's main competitors are Danilo Gentili and Fábio Porchat. Weesibe Bbiri on Delta TV Uganda, hosted by Moses Wamala