Klaatu may refer to:
Klaatu (The Day the Earth Stood Still), the protagonist in the 1951 science fiction film and its 2008 remake Klaatu (band), a Canadian progressive-rock group formed in 1973 Klaatu (album), the U.S. name for their first album, 3:47 EST Klaatu (comics), a Marvel Comics alien The Klaatu Diskos, a young-adult book series by Pete Hautman Klaatu, alien antagonists in Starfleet Orion, a 1978 science-fiction strategy game
See also Klaatu barada nikto, an iconic phrase from The Day the Earth Stood Still