UFO is a 1970-1971 British television

Television

Television is a telecommunication medium for transmitting and receiving moving images that can be monochrome or colored, with accompanying sound...

 science fiction

Science fiction

Science fiction is a genre of fiction dealing with imaginary but more or less plausible content such as future settings, futuristic science and technology, space travel, aliens, and paranormal abilities...

 series about an alien invasion

Alien invasion

The alien invasion is a common theme in science fiction stories and film, in which extraterrestrial life invades Earth either to exterminate and supplant human life, enslave it under a colonial system, harvest humans for food, steal the planet's resources, or destroy the planet altogether.The...

 of Earth, created by Gerry Anderson

Gerry Anderson

Gerry Anderson MBE is a British publisher, producer, director and writer, famous for his futuristic television programmes, particularly those involving specially modified marionettes, a process called "Supermarionation"....

 and Sylvia Anderson

Sylvia Anderson

Sylvia Anderson , born 25 March 1937, is a British voice artist and film producer, most notable for collaborations with Gerry Anderson, to whom she was married from 1962 to 1975....

 with Reg Hill

Reg Hill

Reginald E. Hill was a British television producer and was most prominently associated with the work of puppet animator Gerry Anderson.-Professional life:...

, and produced by the Andersons and Lew Grade

Lew Grade

Lew Grade, Baron Grade , born Lev Winogradsky, was an influential Russian-born English impresario and media mogul.-Early years:...

's Century 21 Productions for Grade's ITC Entertainment

ITC Entertainment

The Incorporated Television Company was a British television company largely involved in production and distribution. It was founded by Lew Grade.-History:...

 company.

UFO first aired in the UK and Canada in 1970 and in US syndication over the next two years (the shows were copyrighted in 1969). In all, 26 episodes, including the pilot

Television pilot

A "television pilot" is a standalone episode of a television series that is used to sell the show to a television network. At the time of its inception, the pilot is meant to be the "testing ground" to see if a series will be possibly desired and successful and therefore a test episode of an...

, were filmed over the course of more than a year, with a five-month production break caused by the ultimate closure of the MGM-British Studios

MGM-British Studios

MGM-British was a subsidiary of Metro-Goldwyn-Mayer initially established at Denham Film Studios in 1936. The films produced there were A Yank at Oxford , The Citadel , Goodbye, Mr...

 in Borehamwood

Borehamwood

-Film industry:Since the 1920s, the town has been home to several film studios and many shots of its streets are included in final cuts of 20th century British films. This earned it the nickname of the "British Hollywood"...

, where the show was initially made.

The Andersons had previously made a number of very successful marionette

Marionette

A marionette is a puppet controlled from above using wires or strings depending on regional variations. A marionette's puppeteer is called a manipulator. Marionettes are operated with the puppeteer hidden or revealed to an audience by using a vertical or horizontal control bar in different forms...

-based children's science fiction series including Supercar

Supercar (TV series)

Supercar was a children's TV show produced by Gerry Anderson and Arthur Provis's AP Films for ATV and ITC Entertainment. 39 episodes were produced between 1961 and 1962, and it was Anderson's first half-hour series. In the UK it was seen on ITV and in the US in syndication...

, Fireball XL5

Fireball XL5

Fireball XL5 is a science fiction-themed children's television show following the missions of spaceship Fireball XL5, commanded by Colonel Steve Zodiac of the World Space Patrol...

, Stingray

Stingray (TV series)

Stingray is a children's marionette television show, created by Gerry and Sylvia Anderson and produced by AP Films for ATV and ITC Entertainment from 1964–65. Its 39 half-hour episodes were originally screened on ITV in the UK and in syndication in the USA. The scriptwriters included Gerry and...

, Thunderbirds

Thunderbirds (TV series)

Thunderbirds is a British mid-1960s science fiction television show devised by Gerry and Sylvia Anderson and made by AP Films using a form of marionette puppetry dubbed "Supermarionation"...

, and Captain Scarlet and the Mysterons

Captain Scarlet and the Mysterons

Captain Scarlet and the Mysterons, often referred to as Captain Scarlet, is a 1960s British science-fiction television series produced by the Century 21 Productions company of Gerry and Sylvia Anderson, John Read and Reg Hill...

. They had also made one live-action science fiction movie, Doppelgänger

Doppelgänger (1969 film)

Doppelgänger is a 1969 British science-fiction film directed by Robert Parrish and starring Roy Thinnes, Ian Hendry, Lynn Loring and Patrick Wymark. Outside Europe, it is known as Journey to the Far Side of the Sun, which is now the more popular title...

, also known as Journey To The Far Side Of The Sun, and now felt ready to move into live-action television and aim at a more adult market.

UFO was the Andersons' first totally live-action TV series.