It's a Knockout was a popular British television gameshow that ran from 1966 to 1982, featuring teams in outlandish costumes (often large latex suits) competing to complete bizarre tasks in absurd games. Teams would be awarded points for their performance in each round, with the team scoring most points winning the game and advancing to the next stage. Teams could double their points in one round by choosing to "play their joker".

For example, team members would attempt to carry buckets full of water over greasy poles or rolling logs to fill up a receptacle. Often, members of the other teams would be allowed to interfere; for example, members of one team may have been permitted to squirt the other teams with water cannons or throw custard pies at them. Commentators included Eddie Waring, David Vine and Stuart Hall.

It's a Knockout was extended into other European countries in 1967 under the French name Jeux Sans Frontieres, a change of name which inspired Peter Gabriel's song "Games Without Frontiers." It was very popular in the UK, acquiring audiences of up to 19 million.

In 1987, It's a Knockout was revived for a one-off charity, It's a Royal Knockout, involving members of the British Royal Family.

In 1999 the show was revived again, this time by Channel 5. This series was introduced by Keith Chegwin. It lasted until 2001.

An Australian version of It's a Knockout ran on the Ten Network from 1985 to 1987. The teams were divided into the Australian states: New South Wales (NSW), Victoria (VIC), Queensland (QLD) and South Australia (SA). The show is being somewhat revived by the same network for 2006 with the title The Friday Night Games.

An American version, called Almost Anything Goes ran on ABC in the summer of 1975, handily winning the time slot on Thursday nights against reruns of The Waltons on CBS and whatever NBC aired. The show replaced the late, un-lamented Saturday Night Live with Howard Cosell in January of 1976 as a mid-season replacement. Sports announcers Charlie Jones and Lynn Shackelford were the play-by-play and color men on this version which featured small towns across America playing the games. Sam Riddle, who was one of the producers, served as field reporter in 1975 along with Dick Whittington, the latter being replaced by Regis Philbin in 1976. Boulder City, Nevada won the 1975 series, and Chambersburg, Pennsylvania won the 1976 series. In a showdown, Boulder City beat Chambersburg and a celebrity all-star team. However, it was up against The Jeffersons on CBS and Emergency! on NBC, and was shortly cancelled thereafter due to low ratings. A children's version called Junior Almost Anything Goes, hosted by Soupy Sales ran in the Saturday morning slot in the fall of that same year, and a syndicated celebrity version, hosted by Bill Boggs ran in 1977.