The Moon landing conspiracy theories claim that some or all elements of the Apollo program and the associated Moon landings were hoaxes staged by NASA and members of other organizations. Various groups and individuals have made such conspiracy claims since the mid-1970s. The most notable claim is that the six manned landings (1969–1972) were faked and that the twelve Apollo astronauts did not walk on the Moon. Conspiracy theorists (henceforth conspiracists) base their claims on the notion NASA and others knowingly misled the public into believing the landings happened by manufacturing, destroying, or tampering with evidence; including photos, telemetry tapes, transmissions, rock samples, and even some key witnesses.

Conspiracists have managed to sustain public interest in their theories for more than 40 years despite there being much third-party evidence for the landings and detailed rebuttals to the hoax claims. Polls taken in various locations have shown that between 6% and 20% of Americans surveyed believe that the manned landings were faked, rising to 28% in Russia. Even as late as 2001, the major television network Fox broadcast a documentary named Conspiracy Theory: Did We Land on the Moon?claiming NASA faked the first landing in 1969 to win the Space Race.
Since the late 2000s, high-definition photos taken by the LROC spacecraft of the Apollo landing sites have captured the lander modules and the tracks left by the astronauts.In 2012, images were released showing the Apollo flags still standing on the Moon.