Extraterrestrial (or Extra-terrestrial) may refer to any object or being beyond (Extra) the planet Earth (terrestrial). It is derived from the Latin extra ("outside", "outwards") and terrestris ("earthly", "of or relating to the Earth"). It may refer to:

• Extraterrestrial life, in scientific context, hypothetical life that exists outside of Earth.
• Fictional extraterrestrials, describes purported alien types recovered from UFO crashes (these are usually assumed to be nonhuman, although theoretically a transplanted culture of humans on another planet would also qualify as extraterrestrials, as with the character of Jonas Quinn on Stargate: SG-1).
• Extraterrestrial (TV program), a show on the National Geographic Channel
• Outer space, the location of things that are "outside Earth"
• E.T. the Extra-Terrestrial