OO

OO or oo may refer to:

• Oo (digraph), a digraph in orthography
• Oô, a commune in France
• OO gauge, a 1:76.2 modelling scale in model railroading
• ‘Ō‘ō, an extinct bird of the genus Moho
• Object-oriented programming (OOP), a computer programming paradigm
• OpenOffice, an open-source application suite
• Official Observer, an appointed amateur radio operator
• Original Oratory, a competitive event in high school forensic competitions
• SkyWest Airlines, IATA code OO
• Belgium, OO (Oscar, Oscar), ICAO aircraft registration prefix
• Oakley, Inc., NYSE stock ticker symbol OO
• OO, the Newtwork Rail depot code for the carriage shed at Old Oak Common TMD
• Ozzy Osbourne, a musician
• O.o or o.O, emoticon used in online chat (appears as two eyes) to describe confused or scared

See also

• 00 (disambiguation)
• OOO (disambiguation)
• ∞, a symbol used to indicate infinity
• ᅇ, an obsolete unit of the Hangul alphabet
• Double-O, a producer and half of hip-hop duo Kidz in the Hall
• Old Order (disambiguation)