| Acronym | Definition |
|---|
| CII | Calculated Ignition Index |
| CII | Central Intelligence Institute (fictional agency) |
| CII | Chartered Insurance Institute (UK) |
| CII | Chemistry International Instrument |
| CII | Children's Institute International |
| CII | Cleveland Industries Inc. |
| CII | Common Integrated Infrastructure |
| CII | Communications and Information Industries |
| CII | Compatibility, Integration, and Interoperability |
| CII | Compatibility, Interoperability, and Integration |
| CII | Computer Intrusion Incident |
| CII | Computer-Integrated Instruction |
| CII | Confederation of Indian Industry |
| CII | Conference Interpreters International (Brussels, Belgium) |
| CII | Configuration Identification/Item Index |
| CII | Configuration Item Identification |
| CII | Configuration Item Index |
| CII | Connecticut Innovations, Inc. |
| CII | Construction Industry Institute (University of Texas) |
| CII | Cornerstone Industry, Inc. |
| CII | Council of Institutional Investors |
| CII | Counter Iranian Influence |
| CII | Criminal Information Index |
| CII | Criminal Investigation Index |
| CII | Critical Infrastructure Information |
| CII | Schedule II Controlled Substance (USA) |
| CII | Call Identity Index |
| CII | Common Interworking Indicator |