Conspiracy theories are hypotheses that accuse a group of people, often a government, of conspiring to hide an occurrence or the true reason behind an occurrence from the people.

Conspiracy theories are often used to explain events and occurrences that seem nonsensical or impossible.

The moon landing is an example of a popular and well-known conspiracy theory. It postulates that the United States government faked the landing of the Apollo 11 on the surface of the moon in 1969, and that humans have thus never reached the moon.

Keynotes about conspiracy theories may explain popular conspiracy theories, seeking to explain why they have gained such traction. They may also seek to disprove conspiracy theories.