| Acronym | Definition |
|---|
| OMI | Organización Marítima Internacional (Spanish: International Maritime Organization) |
| OMI | Ozone Monitoring Instrument |
| OMI | Oblates of Mary Immaculate (religious order) |
| OMI | Old Myocardial Infarction (heart disease) |
| OMI | Organisation Maritime Internationale (French: International Maritime Organization; UN) |
| OMI | Owens Minor, Inc. (various locations) |
| OMI | Object Manipulation Interface |
| OMI | Optical Mode Interface |
| OMI | Office des Migrations Internationales (France) |
| OMI | Owner Move-In |
| OMI | Office of the Medical Investigator (New Mexico) |
| OMI | Oregon Mutual Insurance |
| OMI | Operations Management International, Inc. |
| OMI | Open Model Interface |
| OMI | Open Market, Inc. |
| OMI | Open Messaging Interface |
| OMI | Olford Ministries International |
| OMI | Olympic Medical Institute (UK) |
| OMI | Organizzazione Marittima Internazionale (Italian: International Maritime Organization) |
| OMI | Ocean Mammal Institute |
| OMI | Operator-Machine Interface |
| OMI | Optical Modulation Index |
| OMI | Old Man Intake (automobile air intake modification) |
| OMI | Open Microprocessor Initiative |
| OMI | Open Mind Index (musical taste) |
| OMI | Oocyte Maturation Inhibitor |
| OMI | Offender Management Inspection (UK) |
| OMI | Operations and Maintenance Instructions |
| OMI | Office of Management Information |
| OMI | Ordnance Modifications Instructions (US Navy) |
| OMI | Office of Military Instruction |
| OMI | Orbiter Maintenance Instruction (NASA) |
| OMI | Office of Medical Informatics (various schools) |
| OMI | Operator's Maintenance Instructions |
| OMI | Ohio Mechanical Institute (University of Cincinnati; Ohio) |