| Acronym | Definition |
|---|
| MIO | Marion (Amtrak station code; Marion, WI) |
| MIO | Million (German) |
| MIO | Made in Oklahoma (food manufacturers coalition) |
| MIO | Medical Information Officer |
| MIO | Managed Input Output |
| MIO | Multi Function Input Output |
| MIO | Memory Input Output |
| MIO | Mask Input Output |
| MIO | Maritime Interdiction Operations |
| MIO | Micaceous Iron Oxide |
| MIO | Music Industry Online (music magazine; South Africa) |
| MIO | Modular Input/Output (Hewlett Packard) |
| MIO | Multiple Input-Output |
| MIO | Medical Incident Officer (UK) |
| MIO | Memory Input/Output |
| MIO | Mutsu Institute for Oceanography |
| MIO | Management Information Office |
| MIO | Marine Inspection Office (US Coast Guard) |
| MIO | Multi-Item Optimization (inventory planning) |
| MIO | Mobile Issuing Office (US Navy) |
| MIO | Maximal Incisal Opening |
| MIO | Management Integration Office |
| MIO | Maritime Intercept Operation |
| MIO | Marine Interdiction Operations |
| MIO | Minimal Identifiable Odor |
| MIO | Medical Intelligence Office |
| MIO | Minimally Invasive Osteosynthesis |
| MIO | Material Integration Office |
| MIO | Multi-Image Overcast (robotic flaw detection algorithm) |
| MIO | Major Improvement Opportunities |