Keith Henson is an American engineer and writer known for his work in cryonics and his promotion of the concept of memetics. He co-founded the L5 Society, which advocated for space colonization, and later became an officer of the National Space Society. Henson gained significant public attention for his outspoken criticism of the Church of Scientology, which led to prolonged legal battles. His diverse interests also extend to evolutionary psychology and the development of life extension technologies.