| Abbreviation | Definition |
|---|---|
| IPA | Intergovernmental Personnel Act |
| IPAB | International Program for Antarctic Buoys |
| IPAST | IGOSS Pilot Project on Altimetric Sea-surface Topography Data |
| IPCC | Intergovernmental Panel on Climate Change |
| IPFC | Indo-Pacific Fisheries Commission |
| IPFSC | International Pacific Salmon Fisheries Commission |
| IPHC | International Pacific Halibut Commission |
| IPOD | International Program of Ocean Drilling |
| IPRC | International Pacific Research Center |
| IPS | InterPlanetary Scintillation |
| IPSLN | Indo-Pacific Sea Level Network |
| IPV | Isentropic Potential Vorticity |
| IRD | Ice Rafted Debris |
| IRD | Institut de Recherche pour le Developpement |
| IRD | International Radiation Detector |
| IRICP | International Research Institute for Climate Prediction |
| IRIS | International Recruitment Investigations in the Subarctic |
| IRM | Information Resources Management |
| IRSA | Indus River System Authority |
| ISA | International Seabed Authority |