IMO

IMO may refer to:

• International Mathematical Olympiad
• International Maritime Organization
  • IMO ship identification number, unique identity numbers issued to seacraft (pattern "1234567")
• International Meteorological Organization
• Icelandic Meteorological Office
• International Meteor Organization
• Idiopathic Massive Osteolysis, a name for Gorham's disease
• Independent Market Operator of Ontario, Canada—now the Independent Electricity System Operator (IESO)
• Irish Medical Organisation, the main organisation for doctors in the Republic of Ireland
• Intelligent Medical Objects
• IMO (in my opinion), Internet slang expression
• In the matter of