Guest host

This phrase was popularized on The Tonight Show during Johnny Carson's 30-year reign as host from 1962 to 1992. Toward the end of his tenure, Carson was granted more personal time off, and substitute hosts would be seen on the air more often.

Some guest hosts of The Tonight Show have gone on to host talk shows of their own. Jay Leno would eventually succeed Johnny Carson as Tonight Show host; Joan Rivers went on to host The Late Show Starring Joan Rivers on Fox; and David Brenner hosted the short-lived Nightlife in the late-1980s. Richard Belzer hosted Hot Properties on the Lifetime network in the mid-1980s. When Rivers was fired by Fox in 1988, The Late Show adopted a format consisting only of guest hosts. One of them, Arsenio Hall, went on to host The Arsenio Hall Show, which lasted 1989 to 1994.

The Late Show with David Letterman featured several weeks of guest hosts substituting for David Letterman throughout the 2000s while Letterman recovered from a quintuple bypass surgery and shingles.

The View first became popular with the guest host format in between the arrivals and departures of the program's youngest co-hosts, Debbie Matenopoulos, Lisa Ling, and Elisabeth Hasselbeck. Although a variety of celebrities took turns in the chair, only the younger co-hosts were eligible for the job. During its tenth season, The View began featuring a guest host each day; regular Barbara Walters did not appear with anybody yet was considered eligible to replace Star Jones, who left the previous year. Following the departure of Rosie O'Donnell in 2007 the program looked to return to a panel of five women. The moderator role was given to comedian Whoopi Goldberg in August and Jones' role was given to actress and comedian Sherri Shepherd the week following Goldberg's debut. The View used the guest host format in place of Elisabeth Hasselbeck in 2009 while she was on maternity leave.

• Saturday Night Live was intended originally to have a permanent host, but launched with a guest host format that continues to the present day.
• Live with Kelly and Ryan: the show features guest hosts (usually television or Broadway theater actors) when either Ryan Seacrest or Kelly Ripa is away.
• Later: After Greg Kinnear left the program in 1996 for a film career, NBC's late night talk show went to a "guest host of the week" format featuring mostly young comedians and actors for two years before settling on Cynthia Garrett in 1998.
• Late Late Show: In late 2004, between Craig Kilborn's departure and Craig Ferguson's hiring to CBS's Late Late Show, Late Late rotated through several guest hosts, including Jim Rome, Susan Sarandon and Tim Robbins, David Alan Grier, Ana Gasteyer, Drew Carey, Michael Ian Black, and Craig Ferguson. This format was used again during between the transition from Craig Ferguson to James Corden in the winter of 2015, and for a couple weeks in December 2019 while Corden was on a publicity tour for his appearance in the film adaptation of Cats.
• The Rosie O'Donnell Show: Rosie O'Donnell also used the format during the final season of her own talk show. Comedian Caroline Rhea was given the role of permanent guest host when receiving growing popularity for hosting when O'Donnell was on sick leave the previous year. Following O'Donnell's return, Rhea hosted every Friday edition of the program until it went off the air. Like Joan Rivers with the Tonight Show, Rhea went on to host her own talk show the following year. It, too, was cancelled after only one season.
• The Wendy Williams Show: Despite Williams insisting she would never allow a guest host, actor Jerry O'Connell has filled in for her several times dating back to March 2018 due to illness or personal issues, and hosted a summer test run of a talk show from the same studio for Fox Television Stations that may be considered for syndication in the 2021-22 season.

In the United Kingdom, some shows have guest presenters on a permanent basis. Have I Got News for You has used a different guest presenter for each show since Angus Deayton's departure in 2002. On The Jack Docherty Show in the late 1990s, Jack Docherty was absent so often that the show (retitled Not the Jack Docherty Show) more often than not had a fill-in. When Simon Amstell left his role on Never Mind the Buzzcocks, guest hosts took over the role to December 2013, not unlike a similar incident during Series 18.

• The frequency of guest presenters on certain shows has been parodied by the Onion News Network's Clifford Banes character, who never presents his show for a variety of absurd reasons, and is always replaced by a guest presenter.
• The main plot device of the ESPN Classic Cheap Seats is that "tape librarians" Randy & Jason Sklar are guest hosting the series while the actual host Ron Parker (an in-universe parody of an overly vain SportsCenter anchor played by Michael Showalter) is recovering from the collapse of tape shelving onto him in the show's pilot, a recovery that takes the entire series' 79-episode run. The series' full title is facetiously Cheap Seats: Without Ron Parker.
• Daytime syndicated talk shows of the 1960s and 1970s most often featured a celebrity guest hosting the show alongside the show's host—most notable of these is The Mike Douglas Show.
• World Wrestling Entertainment had weekly guest hosts (either celebrities, WWE Hall of Famers and injured or retired wrestlers) as kayfabe bookers on their flagship show Monday Night Raw.