Passport to Magonia: From Folklore to Flying Saucers is a 1969 book by French-born astronomer and computer scientist Jacques Vallée, published in Chicago by Henry Regnery. It compares modern reports of landed UFOs and their occupants with European fairy lore, accounts of elves and gnomes, religious apparitions and older contact traditions, and argues that the resemblances are too close to ignore. Its title comes from Magonia, the cloud realm described in about 815 by Agobard, bishop of Lyon, who recorded a popular belief that ships from Magonia sailed the clouds and carried off crops felled by storms, a belief he dismissed as foolishness.

One of the book's best-known comparisons concerns the 1961 Eagle River encounter, in which Wisconsin chicken farmer Joe Simonton said the occupants of a landed craft gave him pancakes; Vallée set the account beside Celtic stories of food received from fairies. A long appendix, "A Century of UFO Landings (1868–1968)," catalogued landing and occupant reports across a hundred years. From these parallels Vallée moved away from the extraterrestrial explanation and raised the possibility of a parallel universe coexisting with our own. Later editions include a 1993 reissue, a 2014 Daily Grail Publishing edition and a 2021 limited 50th-anniversary hardcover with a foreword by religious-studies scholar Jeffrey Kripal.

Kripal wrote in September 2026 that the book did much to shift the treatment of the UFO away from a machine in the sky, and that Vallée, disgusted with the American scientific community, wrote it after the Condon Committee. Nick Richardson, writing in the London Review of Books in 2018, traced to Vallée's work the view, held by many ufologists, that UFOs are not alien. The same parallels support opposite readings. Vallée took them as a sign of one persistent phenomenon, while proponents of the psychosocial hypothesis treat them as evidence that UFO reports are shaped by culture and expectation.

The book remains a common entry point: in 2026 newcomers on Reddit listed it among their first UFO books, and commentators on X quoted its passages, including Vallée's speculation that UFOs might be "windows rather than objects" and his warning that unchecked speculation would leave the public prey to charlatans, a line the Vetted podcast's account praised in October. Its pairing of UFO reports with fairies, angels and demons laid the groundwork for Vallée's later control-system hypothesis and remains central to the argument that the phenomenon is far older than the space age.