Exo is a South Korean–Chinese boy band. Exo or EXO may also refer to: exo-, a medical prefix denotes something as "outside" another Exo (album), a 2012 album by Gatekeeper Exo (novel), a novel in the Jumper series by Steven Gould Exo (public transit), a regional public transit agency in greater Montreal, Canada Exo Inc., a company that makes protein bars using flour made from crickets Enriched Xenon Observatory (EXO), a particle physics experiment Exo, a 2017 novel by Fonda Lee The Exo Building, an office building in Dublin, Ireland. See also Ecto (disambiguation) Endo (disambiguation) XO (disambiguation) Exoplanet, a planet outside the Solar System Exoskeleton, an external skeleton that supports and protects an animal's body endo-exo isomerism, a characteristic of some organic compounds