| CSIS | California School Information Services 
| Others |
| CSIS | Canadian Security Intelligence Service
| Others |
| CSIS | Center for Secure Information Systems
| Others |
| CSIS | Center for Spatial Information Science
| Others |
| CSIS | Center for Strategic and International Studies
| Others |
| CSIS | Center for Sustainable Infrastructure Systems
| Others |
| CSIS | Center for Systems Integration and Sustainability
| Others |
| CSIS | Central Scheme of Interest Subsidy
| Others |
| CSIS | Centre for Strategic and International Studies
| Others |
| CSIS | Cisco Secure Integrated Software
| Others |
| CSIS | Civil Service Insurance Society
| Others |
| CSIS | Civil Service Islamic Society
| Others |
| CSIS | Command Support Information System
| Others |
| CSIS | Commercial Sex Information Service
| Others |
| CSIS | Commercial Specialists Insurance Services
| Others |
| CSIS | Community Subsistence Information System
| Others |
| CSIS | Computer Science and Information Systems
| Others |
| CSIS | Container Shipping Information Service
| Others |
| CSIS | Cornerstone School of International Studies
| Others |
| CSIS | Customer Service Information System
| Others |