OCO

OCO or Oco may refer to:

• Oco, a town in Navarre, Spain
• The Oakland Coliseum, formerly branded O.co Coliseum, in California, US
• Old Cornish, a language (ISO 639-3 code: oco)
• Oort cloud object, a distant body of the Solar System
• Orbiting Carbon Observatory 2, a 2014 NASA satellite
  • Orbiting Carbon Observatory, lost to a launch vehicle failure in 2009
• Overseas contingency operation, a type of US military operation
• o.co, Overstock.com, an online store
• One cancels other, a type of financial trading instruction
• O=C=O, the structural formula for carbon dioxide
• Offensive cyber operations, a US Air Force term