UFO is a 1956 American semi-documentary about the development of the UFO phenomenon in the United States. Clips from the documentary have often been used in other UFO documentaries and television episodes related to UFOs.

UFOs: Past, Present, and Future is a 1974 documentary film that examines several prominent UFO sightings from the post-war to contemporary era. It was re-released in 1976 and 1979 under the title UFOs: It Has Begun to coincide with renewed interest in the subject due to the release of Steven Spielberg's Close Encounters of the Third Kind. It is based on the book UFOs: Past, Present, and Future by Robert Emenegger.