| CSSS | California School Staff Survey 
| Others |
| CSSS | Canadian Society of Soil Science
| Others |
| CSSS | Cape Sable Seaside Sparrow
| Others |
| CSSS | Carroll Shelby Signature Series
| Others |
| CSSS | Center For Solid State Science
| Others |
| CSSS | Chemical Sector Security Summit
| Others |
| CSSS | Commission to Strengthen Social Security
| Others |
| CSSS | Commonwealth Shared Scholarship Scheme
| Others |
| CSSS | Community of Sahel-Saharan States
| Others |
| CSSS | Community Schools Student Services
| Others |
| CSSS | Complex Systems Summer School
| Others |
| CSSS | Comprehensive Student Support System
| Others |
| CSSS | Computer Science Student Society
| Others |
| CSSS | Computer Sound Security System
| Others |
| CSSS | Computerized Spelling Sensitivity System
| Others |
| CSSS | Copenhagen Symposium On Separation Sciences
| Others |
| CSSS | Council of State Science Supervisors
| Others |
| CSSS | Czech and Slovak Simulation Society
| Others |