Lloyd Pye (1946-) is an American author and researcher largely concerned with an alternative theory of the origin of human life, belonging to a field which he terms "alternative knowledge".

Pye is author of four books, including Everything You Know Is Wrong - Book One: Human Origins. He also conducts original research into his theories, gives lectures, and has made television appearances on The Learning Channel, National Geographic Channel, Extra, Animal Planet, and The Richard and Judy Show in the United Kingdom. In his work he argues that humans did not evolve from earlier organisms, but rather originated (at least partly) from deliberate intervention by extraterrestrial life (an intervention theory).

Pye was born in Houma, Louisiana. He studied psychology at Tulane University in New Orleans, before joining the U.S. Army as a military intelligence specialist.

In addition to his other works, Pye has written two noveles: A Darker Shade of Red, based on his college football career at Tulane and Mismatch, a high-tech thriller about phone phreaking, computer hacking, and submarine warfare.

In his nonfiction work, Pye focuses on aspects of cryptozoology, especially hominoid cryptids such as bigfoot and yeti. Pye developed these themes in Everything You Know Is Wrong in 1998. Here he claims that these animals are Earth's only indigenous bipedal primates, and that early hominids such as Neanderthals and Australopithecines are not intermediates in human evolution.

From this premise, Pye concludes that early hominids could not have been the ancestors of modern humans. Combining his ideas with those of ancient astronaut theorist Zecharia Sitchin, he proposes an alternative model for the origin of Homo sapiens - that of deliberate planting by alien beings, or of interbreeding with extraterrestrials. Pye hypothesises that the first such modern human peoples were the ancient Sumerians, whom he claims had knowledge of aspects of modern astronomy such as the existence of Neptune, Uranus, andPluto.

In the late 1990s, Pye obtained a curiously shaped human child's skull from a couple in El Paso, Texas. The skull was reportedly found in a mine tunnel in northern Mexico, buried beside a skeleton of an morphologically typical human female adult lying exposed on the floor of the mine tunnel. The unusual skull has an enlarged though symmetrical cranium, and while it contains most of the complement of normal human bones, they are greatly distorted in shape, as for instance it is without an external occipital protuberance. Carbon 14 dating shows that the skull is 900 years old + or - 40 years. Pye proposes that the abnormal skull is the product of a human/alien crossbreeding program. He refers to this being as a "Starchild" and the skull as the "Starchild skull". Pye has subsequently arranged for funding and scientific testing in an attempt to demonstrate that the skull's genetic heritage is extraterrestrial.

Pye claims that the human genetic array as it exists today is "only 150,000 to 200,000 years old.