The Simple English Wiktionary has a definition for: O₂.

O2, O-2, o2, O₂, or O² may refer to:

• O₂, the common allotrope of the chemical element oxygen
• O2, an EEG electrode site according to the 10–20 system
• SGI O2, a Unix workstation computer
• UOC O2, institutional repository of the Open University of Catalonia

• The O2, an entertainment district in London, England
  • The O2 Arena, the arena within The O2
• O2 Arena (Prague) or Sazka Arena, an arena in Prague, Czech Republic
• O2 Centre, an indoor shopping and entertainment centre on Finchley Road, London, England
• O2 Residence, a part of the Jumeirah Lake Towers in Dubai, United Arab Emirates
• O2 World (Berlin), an indoor arena in Berlin, Germany
• O2 World (Hamburg), an indoor arena in Hamburg, Germany
• Otoyol 2, a motorway in Turkey called "O2"
• The O2 (Dublin), the former name of 3Arena

• O₂ (FireHouse album) (2000) album of the rock band FireHouse
• O2 (O-Town album) (2002) album by American boy band O-Town
• O₂ (Tonéx album) (2002) album by Gospel singer Tonéx
• O2: Avalon Remixed, a 2002 album by Avalon
• O2 (Son of Dave album), 2006 album by Son of Dave

• "O2", a song by Orange Range from Panic Fancy
• "O2", a 2002 song by Sleater-Kinney from One Beat

• Ö2, a radio service for Austria and South Tyrol
• O2, a character in Kirby 64: The Crystal Shards

• O₂, trading name for Telefónica Europe, a European telecommunications provider
  • O2 Store, a chain of retail stores owned and operated by Telefónica Europe, with regional subsidiaries:
  • O2 (Ireland), merged into Three Ireland
  • O2 (UK)
  • O2 Czech Republic
  • Telefónica Germany
  • Telefónica Slovakia
• O2 Academy, a chain of music venues
• O2 Global Network, an international network for sustainable design
• O2 Wireless USA or H2O Wireless, a prepaid wireless service by Locus Telecommunications
• O2TV, a Russian independent socially political TV channel

• Cessna O-2 Skymaster, a military twin-engine light aircraft
• Douglas O-2, a military single-engine observation biplane
• O 2-class submarine, a class of submarines of the Royal Netherlands Navy
• Oldershaw O-2, a glider
• SP&S Class O-2, a 1910 steam locomotives class
• USS O-2 (SS-63), a 1918 United States O class submarine

• O-2, a pay grade in the US uniformed services
  • First Lieutenant in the Army, Air Force, and Marine Corps
  • Lieutenant (junior grade) in the Navy, Coast Guard, Public Health Service Commissioned Corps, and NOAA Commissioned Officer Corps

This disambiguation page lists articles associated with the title O2. If an internal link led you here, you may wish to change the link to point directly to the intended article.