The Starchild skull is an abnormal human skull which was found in Mexico. It is primarily known through paranormal researchers' claims that it represents evidence of extraterrestrial contact.

Scientific testing has shown the skull is that of a male child who died approximately 900 years ago. DNA testing has shown that both his parents were human.

The starchild skull came into the possession of Ray and Melanie Young of El Paso, Texas, who entrusted it to Lloyd Pye, a writer and lecturer in what he calls the field of alternative knowledge, in February 1999. According to Pye, the skull was found around 1930 in a mine tunnel about 100 miles (160 km) southwest of Chihuahua, Chihuahua, buried alongside a normal human skeleton which was exposed and lying supine on the surface of the tunnel.

The skull has garnered great interest with those interested in UFOs and alien visitation. Some contend that it is the skull of an alien, or a human/alien hybrid, based on the shape of the skull bearing similarities to the common representation of aliens as "Greys". Proponents of a paranormal explanation for the skull's origin reject hypothesis involving non-paranormal causes such as cradle boarding or hydrocephaly, and contend that it has many other abnormalities such as the thickness, density, and strength of the bone that argue against the skull being human.