IMO

IMO or Imo may refer to:

Maritime

 * International Maritime Organization
 * IMO number, a unique identity number issued to seacraft (pattern "1234567")
 * SS Imo, a 1889 ship involved in the Halifax Explosion

Meteorology

 * International Meteorological Organization
 * Icelandic Meteorological Office

Other

 * Irish Medical Organisation, the main organisation representing doctors in Ireland
 * Intelligent Medical Objects, a privately held company specializing in medical vocabularies
 * Isomaltooligosaccharide, a mixture of short-chain carbohydrates which has a digestion-resistant property
 * Idiopathic Massive Osteolysis, a name for Gorham's disease, a rare bone disease
 * International Mathematical Olympiad
 * International Meteor Organization
 * Imo State, Nigeria
 * imo.im, a video calling and instant messaging app
 * IMO (in my opinion), an Internet slang expression