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. The show was produced in 1962 by husband and wife team Gerry and Sylvia Anderson through their company APF, in association with ATV for ITC Entertainment. While developing his new show, Anderson thought a brand of motor oil—Castrol XL—had an interesting sound. A phonetic change created the name "Fireball XL", with the "-5" added as the title seemed a bit flat without the numeral.

The show featured the Andersons' Supermarionation, a form of puppetry first introduced in Four Feather Falls and Supercar and used again in their subsequent productions such as Stingray and Captain Scarlet. Thirty-nine black and white half-hour episodes of Fireball XL5 were made on 35mm film: all future Anderson series were produced in colour.

Several Anderson series have been shown in syndication in the US, but Fireball XL5 is the only Anderson series to have run on a US network. NBC ran the series in its Saturday morning children's block from 1963 through to September 1965.

A similar programme often confused with Fireball XL5 is Space Patrol, produced by Gerry Anderson's ex business partner and co-founder of AP Films, Arthur Provis due to a number of similarities and settings.