| Acronym | Meaning |
| ICAM-1 | Intercellular Adhesion Molecule-1 |
| ICAME | International Commission On Application Of Moessbauer Effect |
| ICAO | International Civil Aviation Organization |
| ICAP | Inductively Coupled Argon Plasma |
| ICAPES | Inductively Coupled Argon Plasma Emission Spectrometry |
| ICARUS | Imaging Cosmic And Rare Underground Signal |
| ICAT | Isotope-coded Affinity Tag |
| ICB | Ionized Cluster Beam |
| ICBA | Improved (final-state) Coulomb Born Approximation |
| ICBN | International Code Of Botanical Nomenclature |
| ICBO | International Conference Of Building Officials |
| ICC | Interstitial Cells Of Cajal |
| ICC | Intrahepatic Cholangiocarcinoma |
| ICC | Integrated Cell Culture |
| ICC | Interstate Commerce Commission |
| ICC | Ignition Control Compound |
| ICC | Intraatomic Correlation Correction |
| ICCA | International Council Of Chemical Associations |
| ICCD | Intensified Charge-coupled Device |
| ICCIDD | International Council For Control Of Iodine Deficiency Disorders |
| ICCP | International Climate Change Partnership |
| ICCP | International Committee For Coal Petrology |
| ICCVAM | US Interagency Coordination Committee On The Validation Of Alternative Methods |
| ICD | International Classification Of Diseases |
| ICD | Implantable Cardioverter Defibrillator |
| ICD | Induced Circular Dichroism |
| ICDD | International Center For Diffraction Data |
| ICDH | Isocitrate Dehydrogenase |
| ICDW | Incommensurate Charge Density Wave |
| ICE | International Common Elements |
| ICE | Interleukin 1beta-converting Enzyme |
| ICEAS | Intermittent Cycle Extended Aeration System (activated Sludge) |
| ICES | International Council For The Exploration Of The Sea |
| ICF | Inertial Confinement Fusion |
| ICF-CI | Interacting Correlated Fragment-CI (wave Function) (see Also SA-MCSCF) |
| ICGCC | Integrated Coal Gasification Combined Cycle Plant |
| ICH | International Conference On Harmonization |
| ICHAZ | Intercritical Heat-affected Zone |
| ICI | Industrial, Commercial, And Institutional |
| ICISS | Impact Collision Ion Scattering Spectroscopy |
| ICL | Interface Control Layer |
| ICLAS | Intracavity Laser Absorption Spectroscopy |
| ICLS | Intracavity Laser Spectroscopy |
| ICM | Institute For Crisis Management |
| ICM | Injection Compression Molding |
| ICM | Inner Cell Mass |
| ICM | Intracluster Medium |
| ICMA | Immunochemiluminometric Assay |
| ICMR | Indian Council Of Medical Research |
| ICMRCI | Internally Contracted MR-CI |