| Acronym | Definition |
|---|
| CSIS | Canadian Security Intelligence Service |
| CSIS | Center for Strategic & International Studies |
| CSIS | Computer Science and Information Systems |
| CSIS | Center for Spatial Information Science (University of Tokyo; Japan) |
| CSIS | Commercial Sex Information Service |
| CSIS | California School Information Services |
| CSIS | Center for Secure Information Systems |
| CSIS | College des Sciences de l'Ingenierie et des Systèmes (French: College of Engineering and Systems Sciences; Paris-Saclay University; Paris, France) |
| CSIS | Container Shipping Information Service (public awareness initiative) |
| CSIS | Canadian Society for Industrial Security, Inc. |
| CSIS | Civil Service Insurance Society (United Kingdom) |
| CSIS | Canadian Society for Italian Studies |
| CSIS | Case-Shiller Indexes |
| CSIS | Complete Sentient Information Systems (Canada) |
| CSIS | Customer Service Inquiry System |
| CSIS | Credited Structures Inventory System (US FEMA) |
| CSIS | Centre for Strategic Information Systems |
| CSIS | Community Safety Information System |
| CSIS | Citigroup Security and Investigative Services |
| CSIS | Customer Service Information System |
| CSIS | Central Secondary Item Stratification |
| CSIS | College Student Insurance Service |
| CSIS | China's Species Information System |
| CSIS | Children's Services Information Service |
| CSIS | Center for Study of Intimate Systems |
| CSIS | Coping Strategies Inventory for Statistics |
| CSIS | Combined Spectral Interpolation Synthesis |
| CSIS | Collectible Specialties Import Services |
| CSIS | Constituent Services Information System (Georgia) |
| CSIS | Council of Senior Islamic Scholars (Saudi Arabia) |