| Acronym | Definition |
|---|
| IOR | Instituto de Obras Para la Religión (Spanish: Institute for Works of Religion) |
| IOR | Index of Reliability |
| IOR | Instructor of Record (various universities) |
| IOR | Interoperable Object Reference |
| IOR | Interorganizational Relationship |
| IOR | Istituto Ortopedico Rizzoli (Rizzoli Orthopaedic Institute, Italy) |
| IOR | Ibm Onsite Repair |
| IOR | Input Output Register |
| IOR | Input Output Real |
| IOR | Input Output Read |
| IOR | Input Output Resource |
| IOR | Index of Refraction |
| IOR | Institute of Recruiters (UK) |
| IOR | Inclusive Or |
| IOR | Indian Ocean Rim |
| IOR | Improved Oil Recovery |
| IOR | Institute of Refrigeration (UK) |
| IOR | Inhibition of Return |
| IOR | Indian Ocean Region |
| IOR | Importer of Record (customs) |
| IOR | Increased Oil Recovery |
| IOR | Istituto Per Le Opere Di Religione (Vatican Bank) |
| IOR | International Osteopathic Research (France) |
| IOR | International Offshore Rule (sailing) |
| IOR | Inspector of Record (construction term) |
| IOR | Indian Other Rank |
| IOR | Independent Order of Rechabites (est. 1835) |
| IOR | Impact of Relationship (social media) |
| IOR | Institute of Operational Risk |
| IOR | International Orientation Resources |
| IOR | Ideas of reference |
| IOR | Immediate Operational Requirement |
| IOR | Initial Operating Report (US FEMA) |
| IOR | Interobserver Reliability |
| IOR | Input/Output Read |
| IOR | International Ocean Racing (Association) |
| IOR | Industry Optic Romania |
| IOR | Investigator of Record |
| IOR | Institute of Religion |
| IOR | Intelligent Office Repeater |
| IOR | Increment Operations Review |
| IOR | Indicated Outcome Report |
| IOR | Issue on Request |
| IOR | Isle of Rhythm (Belgian music event) |
| IOR | Issue On Requisition |