Pseudoarchaeology, a form of pseudoscience, refers to the ideologically-driven, usually sensational interpretation of the past outside of a critical, scientific framework. It is used by many to refer to religious perspectives they see as non-scientific (Creationism often receives this label) as well as to the pursuit of untestable hypotheses such as the influence of UFOs or ancient astronauts on past civilizations. Pseudoarchaeology includes the investigation of theories generally discarded by scientific investigators, such as the existence of Noah's Ark on Mount Ararat, lost continents such as Atlantis or Lemuria, and the idea of direct contact between the ancient civilizations of Egypt and the Maya. It can also include scientific investigations in which the ability to maintain a critical, scientific perspective is diminished by religious belief. An example that is frequently cited would be research on the Shroud of Turin.

In a characteristic approach that is symptomatic of many other pseudosciences, an a priori conclusion is established beforehand, and fieldwork is undertaken explicitly to corroborate the theory in detail (see the 1947 Kon-Tiki adventure of Thor Heyerdahl). Such convictions may lead to pious fictions, such as the Piltdown Man fraud and some spurious "Viking" relics in North America. Supernatural guidance of archaeological finds is documented as early as the 326CE expedition led by Helena, mother of Constantine the Great to recover the cross outside Jerusalem, published by Eusebius.

Practitioners of pseudoarchaeology often rail against academic archaeologists and established scientific methods of hypothesis testing and empirical observation, claiming that scientists have somehow overlooked or disregarded critical pieces of evidence. They will sometimes go so far as to invoke inspired knowledge, such as the receipt of information through divine inspiration, dreams, or psychic phenomena such as ESP. Many individuals who received the label of "pseudoarchaeologist" have demonstrated a greater interest in personal gain than in the pursuit of objective knowledge.

There are a number of legitimate archaeological sites that have long been the focus of a disproportionate amount of unscientific speculation in the context of pseudoarchaeology. Among these are Stonehenge, the Great Pyramid, the Sphinx, Easter Island, Teotihuacan, Palenque, Chichén Itzá, and the stone balls of Costa Rica. For some reason, other archaeological wonders such as the Great Wall of China or the spectacular burials at Xian have not received this type of attention.

Some of the defenders of "pseudoarchaeology" respond to the above criticisms by noting that scientific truths frequently are ridiculed when they are first proposed: they object further to the term "pseudoarchaeology" as being pejorative.