From Wikipedia, the free encyclopedia

Io most commonly refers to:

  • Io (moon), a moon of Jupiter
  • Io (mythology), daughter of Inachus in Greek mythology, and lover of Zeus who was turned into a cow

Io, IO, iO, I/O, i/o, or i.o. may also refer to:

Arts, entertainment and media[edit]

Fictional elements[edit]



Theatre and opera[edit]

  • Io (opera), an unfinished acte de ballet (opera) by Jean-Philippe Rameau
  • iO Theater (ImprovOlympic), a theater in Chicago, Illinois, dedicated to improvisational comedy
  • IO West, a Los Angeles theater associated with the Chicago iO

Other uses in arts, entertainment and media[edit]

Business and economics[edit]


  • i.o., in illo ordine, Latin phrase meaning "respectively" ("in that order")
  • Io (princely title), a particle of a title used by Moldavian and Wallachian Princes-regnant
  • Ido language (ISO 639-1 language code IO), a constructed language
  • Indirect object, the object that is the recipient of an action (by a verb)
  • Yo, also referred to as Io


  • Io (mythology), daughter of Inachus in Greek mythology, and lover of Zeus who was turned into a cow
  • Io, an alternate spelling of the nereid Ino, later known as Leukothea, who in the Odyssey gave Odysseus a veil that allowed him to breathe underwater
  • Io Matua Kore, in some Māori traditions the supreme god


  • Io Murota (室田 伊緒, born 1989), Japanese shogi player
  • Io Sakisaka (咲坂 伊緒), Japanese manga artist
  • Io Shirai (born 1990), Japanese professional wrestler
  • Iou Kuroda (黒田 硫黄, born 1971), Japanese manga artist
  • iO Tillett Wright (born 1985), American artist, director, photographer, writer, film maker, activist, and actor

Places on Earth[edit]

Science and technology[edit]


Biology and medicine[edit]


  • .io, the Internet country code top-level domain (ccTLD) for the British Indian Ocean Territory
  • Io (programming language), a pure object-oriented programming language
  • IO.SYS, a system file in Microsoft DOS and Windows 95, 98 and ME
  • Indistinguishability obfuscation, a cryptographic tool to obscure computer code
  • Input/output, the collection of interfaces that different functional units of an information processing system use to communicate with each other

Other uses in science and technology[edit]

Other uses[edit]

See also[edit]