| Acronym | Definition |
|---|
| IOP | Intensive Out Patient (treatment program) |
| IOP | Institute Of Physics |
| IOP | Intraocular Pressure |
| IOP | Institute of Psychiatry |
| IOP | Intensive Outpatient Program |
| IOP | Intensive Outpatient Program (psychotherapy) |
| IOP | Interoperability |
| IOP | In Original Packaging |
| IOP | Institute of Politics (Harvard University) |
| IOP | Isle of Palms (South Carolina) |
| IOP | Indirect Object Pronoun (education) |
| IOP | Increased Intraocular Pressure |
| IOP | Input Output Port |
| IOP | Input Output Platform |
| IOP | Interoperability Provider |
| IOP | Input Output Processor |
| IOP | Institute of Packaging (UK) |
| IOP | Institute of Oriental Philosophy (Japan) |
| IOP | International Outreach Program (various locations) |
| IOP | Institute of Plumbing |
| IOP | International Online Pharmacy |
| IOP | In-Orbit Plane (US NASA) |
| IOP | International Opportunities Program |
| IOP | International Organisation of Palaeobotany |
| IOP | Internal Operating Procedure |
| IOP | Internal Occipital Protuberance (anatomy) |
| IOP | Institute of Philosophy |
| IOP | Intensive Operational Period |
| IOP | International Organization of Psychophysiology (UN) |
| IOP | Input/Output Package |
| IOP | Institute of Paper |
| IOP | Inherent Optical Property |
| IOP | Innocent Owner/Operator Program |
| IOP | Intensive Operating Period |
| IOP | Internal Oral Presentation (examination) |
| IOP | Institutional Operating Plan |
| IOP | Intelligent Operator Panel (Siemens) |
| IOP | Intense Observation Period |
| IOP | Instrument of Power |
| IOP | Increased Offertory Program (church offerings; various locations) |
| IOP | Individual Oral Presentation (International Baccalaureate assignment) |
| IOP | Input/Output Parameter |
| IOP | Interim Operating Procedure |
| IOP | Inanimate Objects Party |
| IOP | Infrastructure Optimization Project |
| IOP | Interface Operating Procedure |
| IOP | Installation Operating Program |
| IOP | Informational One-Pager |
| IOP | Internal Operating Profit |
| IOP | Item of Priority |
| IOP | Intensive Observation/Observing Period |
| IOP | Individual Owner's Plan (surveying; Canada) |
| IOP | Information Operations Platform (US Air Force) |
| IOP | Integrated Office Package |
| IOP | Instrument Operating Procedure |