| Abbreviation | Definition |
|---|---|
| CSM | Command Sergeant Major - Army |
| CSN | Confederate States Navy |
| CSO | Central Statistical Office |
| CSO | Contract Standing Order |
| CSOS | Controlled Substance Ordering System |
| CSOSA | Court Services and Offender Supervision Agency |
| CSP | Civil Service Preparation |
| CSPO | Competitive Sourcing Program Office |
| CSRA | Civil Service Reform Act of 1978 |
| CSREES | Cooperative State Research, Education, and Extension Service |
| CSRS | Civil Service Retirement System |
| CSSP | Cigarette Smoking Strictly Prohibited |
| CSSR | Central Server for Statistical Reporting |
| CT | Counter Terrorism |
| CTC | Child Tax Credit |
| CTC | Counter- Terorism Centre |
| CTC | Cyber Threat Center |
| CTD | Civilian Travel Determination |
| CTF | Combat Terrorism Financing |
| CTF | Combined Test Force |