| CSSI | Campus Student Sustainability Initiatives 
| Others |
| CSSI | Caribbean Safe Schools Initiative
| Others |
| CSSI | Carleton Summer Science Institute
| Others |
| CSSI | Cell Stress Society International
| Others |
| CSSI | Center for Silicon System Implementation
| Others |
| CSSI | Center for Space Standards Innovation
| Others |
| CSSI | Center for Strategic
| Others |
| CSSI | Center for Strategic Scientific Initiatives
| Others |
| CSSI | Charter School Support Initiative
| Others |
| CSSI | Chattanooga Shooting Supplies Inc
| Others |
| CSSI | Child Support Savings Initiative
| Others |
| CSSI | Collegiate Shooting Sports Initiative
| Others |
| CSSI | Colorado School Support Initiative
| Others |
| CSSI | Comprehensive School Safety Initiative
| Others |
| CSSI | Computational Social Science Initiative
| Others |
| CSSI | Computational Social Science Institute
| Others |
| CSSI | Computer Science Summer Institute
| Others |
| CSSI | Computer Services and Solutions Inc
| Others |
| CSSI | Computer Solutions and Software International
| Others |
| CSSI | Computer Support Services Inc
| Others |
| CSSI | Consolidated Storage Solutions Inc
| Others |
| CSSI | Corporate Special Services Inc
| Others |
| CSSI | Correctional Services of Solomon Islands
| Others |
| CSSI | Creation Science of Saskatchewan Inc.
| Others |
| CSSI | Creative Surveillance Solutions Inc
| Others |
| CSSI | Critical Skills Shortage Initiative
| Others |
| CSSI | Cross sector social interactions
| Others |
| CSSI | CSS Selector Scene Investigation
| Others |
| CSSI | Culinary Sales Support Inc
| Others |
| CSSI | Cyber Solutions Services Inc
| Others |