OOO

OOO or Ooo may refer to:

Frequently used abbreviations

• OoO, an abbreviation for Out of Office, a phrase often used in professional contexts to indicate that someone is unavailable for work (usually because they are on vacation)
• ООО, a type of private limited company (общество с ограниченной ответственностью) in Russia

Arts, entertainment, and media

• Kamen Rider OOO, a 2010–11 tokusatsu series
• Kamen Rider OOO (character), a fictional character from the tokusatsu series of the same name
• The Land of Ooo, the setting of Adventure Time
• OOO, the production code for the 1972 Doctor Who serial The Time Monster
• "Ooo", a song by !!! from their 2015 album As If
• "Ooo", a track from the soundtrack of the 2015 video game Undertale by Toby Fox
• O.O.O (Over&Over&Over), theme song of Girls Planet 999 and Kep1er version, recorded in First Impact

Computing and networking

• .OOO, an Internet top-level domain
• OpenOffice.org, a discontinued office application suite
• Out-of-order execution, a paradigm in microprocessors

Other uses

• OOO gauge, an old British model railway scale
• Order of operations, mathematical rules for conventions to evaluate expressions
• Object-oriented ontology, a metaphysical school of thought
• O-O-O, long (or queenside), castling, in Portable Game Notation

See also

• Triple-O (disambiguation)
• 000 (disambiguation) (three zeros)
• O00, the Alturas Municipal Airport
• One on One (disambiguation)
• Out of Order (disambiguation)
• Three Rings Design, an online game developer
• OO (disambiguation)