| Abbreviation | Definition |
|---|---|
| IOC | Indian Ocean Climate |
| IOC | Intergovernmental Oceanographic Commission |
| IOCARIBE | Intergovernmental Oceanographic Commission Sub-commission for the Caribbean and Adjacent Regions |
| IOCI | Indian Ocean Climate Initiative |
| IOCM | Integrated Ocean and Coastal Mapping |
| IOC-TEMA | Inter-Governmental Oceanographic Commission Committee for Training, Education, and Mutual Assistance in the Marine Sciences |
| IOC-VCP | IOC Voluntary Cooperation Program |
| IOCZA | Inter-Ocean Convergence Zone |
| IODC | Indian Oceanographic Data Centre |
| IODE | International Oceanographic Data and Information Exchange |
| IODM | Indian Ocean Dipole Mode |
| IODP | Integrated Ocean Drilling Program |
| IOF | International Oceanographic Foundation |
| IONA | Islands Of the North Atlantic |
| IONS | Institute of Oceanography, Nova Scotia |
| IOP | Intensive Observation Period |
| IOPAS | Institute of Oceanology, Polish Academy of Sciences |
| IOS | Institute of Ocean Sciences |
| IOS | Institute of Oceanographic Sciences |
| IOSDL | Institute of Oceanographic Sciences, Deacon Laboratory |