The Investigator is a 1973 British television pilot devised, produced and directed by Gerry Anderson, creator of Thunderbirds and other Supermarionation TV series of the 1960s. It centres on two American youths, John and Julie, who have been recruited by an extragalactic being called "the Investigator" to aid his self-appointed task of ridding Earth of evil and corruption. Miniaturised and given special knowledge and abilities, they take on Stavros Karanti, an unscrupulous businessman plotting to steal a priceless painting from a Maltese cathedral. Shane Rimmer and Sylvia Anderson voice John and Julie, who are represented by two-foot-tall (0.61 m) marionette puppets, while Charles Thake and Peter Borg appear as Karanti and his minion Christoph.

The pilot marked Gerry Anderson's first use of puppets since The Secret Service (1969). Written by his wife Sylvia from a story by Rimmer, it was filmed on location in Malta between the production of The Protectors and a planned second series of UFO (which would later be made as Space: 1999). Filming was complicated by numerous technical and logistical difficulties and the crew were unable to finish the shoot. The pilot was assembled from the incomplete footage but Anderson, disappointed with the result, abandoned his idea of pitching it to NBC as the basis for a new Supermarionation series. Unaired to date, the pilot has received a negative response from commentators. It was released on DVD in 2012 and 2015.