| Acronym | Definition |
|---|
| CSSO | Contractor Special Security Officer |
| CSSO | Chief State School Officer |
| CSSO | Chief Student Services Officer (California community colleges) |
| CSSO | Clotted Symmetric Sexual Organ (Japanese band) |
| CSSO | Computer System Security Officer |
| CSSO | Customer Service, Sales & Operations |
| CSSO | Computer Special Security Officer |
| CSSO | Communications-Computer Systems Security Officer |
| CSSO | CLIC (Cancer and Leukaemia in Childhood) Sargent Symphony Orchestra (UK) |
| CSSO | Child Safety Support Officer (Australia) |
| CSSO | Compliance Sampling and Support Organization |
| CSSO | Combat Service Support for Operations |
| CSSO | Cantorial School Student Organization (Jewish Theological Seminary) |