ESO (disambiguation)

The European Southern Observatory is an astronomical research organisation.

ESO may also refer to:
 * Employee stock option (also: executive stock option)
 * Ether Saga Odyssey, a fantasy massively multiplayer online role-playing game
 * The Elder Scrolls Online, a fantasy massively multiplayer online role-playing game
 * Existential second-order logic
 * ESO (motorcycles)
 * Eso (town), Orhionmwon, Edo State, Nigeria

Organisations

 * European Standardisation Organisations: CEN (European Committee for Standardization), CENELEC (European Committee for Electrotechnical Standardisation) and ETSI (European Telecommunications Standards Institute)
 * Ensemble Studios Online
 * Edmonton Symphony Orchestra
 * Evergreen Symphony Orchestra, an orchestra in Taiwan
 * Eteläsuomalainen osakunta, a student nation at the University of Helsinki
 * Libyan External Security Organisation
 * External Security Organisation, the Ugandan external secret service
 * École secondaire d'Oka, a public high school in Oka, Quebec, Canada
 * National Grid Electricity System Operator (ESO), British electricity transmission network operator

Music

 * English Symphony Orchestra and English String Orchestra, two related classical orchestral ensembles
 * Eso-Charis, Christian metal band (and self-titled album)
 * Bliss n Eso, Australian hip hop group