| Acronym | Definition |
|---|
| IMO | In My Opinion |
| IMO | In Memory Of |
| IMO | International Maritime Organisation (UN) |
| IMO | International Mathematical Olympiad |
| IMO | Im Moment (German: In This Moment) |
| IMO | International Meteor Organization |
| IMO | I'm Moving On |
| IMO | In Mijn Ogen (Dutch: in My Eyes) |
| IMO | Internet Mail Only |
| IMO | Irish Medical Organisation |
| IMO | International Money Order |
| IMO | Independent Electricity Market Operator |
| IMO | Independent Marketing Organization (insurance) |
| IMO | Independent Market Operator |
| IMO | Information Management Officer |
| IMO | Intelink Management Office (US DoD) |
| IMO | Intergovernmental Maritime Organization (obsolete) |
| IMO | Interactive Mathematics Online |
| IMO | Immune Modulatory Oligonucleotides |
| iMO | Instant Money-Order |
| IMO | Institut für Mathematische Optimierung (Universität Magdeburg, Germany) |
| IMO | Insaat Mühendisleri Odasi (Turkish: Chambers of Civil Engineering) |
| IMO | Idaho Mounted Orienteering (club) |
| IMO | International Market Opportunities |
| IMO | Intramural Order |
| IMO | Incident Management Officer |
| IMO | Intermediate Math Open |
| IMO | Installation Maintenance Officer |
| IMO | Integrated Molecular Orbital |
| IMO | Installation Management Office |
| IMO | Installation Mobility Officer |
| IMO | Intensive Management Office |
| IMO | Imaobong Missionary Outreach |
| IMO | Information Media Outlet |
| IMO | Intermediate Military Objective (US DoD) |
| IMO | Icelandic Meteorological Office |
| IMO | Insurance Marketing Organization (various companies) |