AP Films was a British independent film production company of the 1950s and 1960s. It was formed in 1957 (as Pentagon Productions) by editor-director Gerry Anderson and cinematographer Arthur Provis , in partnership with producer Reg Hill and cinematographer John Read . Provis left the partnership after a few years later and Anderson's wife Sylvia subsequently became a partner.

The company became world-famous with the string of imaginative children's action-adventure marionette series it produced for the British television companies Granada and ATV. APF produced three series for Granada — The Adventures of Twizzle , Torchy The Battery Boy and Four Feather Falls — but its best known productions, for ATV, were the futuristic sci-fi action adventure series Supercar (1960-61), Fireball XL5 (1962), Stingray (1964) — the first British children's TV series to be made in colour — and Thunderbirds (1964-66), which was by far their most famous and successful production.

After the completion of Fireball XL5, ATV owner Lew Grade purchased the company, with Grade becoming managing director, and the Andersons, Hill and Read remaining as directors. The company was renamed Century 21 Productions in 1964, when production commenced on Thunderbirds. As Century 21, the company produced two Thunderbirds feature films, and two more Supermationation series for ATV, Captain Scarlet and The Mysterons and Joe 90. This was followed by the feature film Doppelganger (aka Journey To The Far Side of the Sun ), their first live action TV series, UFO (1969).