| CIOC | Canadian International Oil Corp 
| Others |
| CIOC | Canadian International Organ Competition
| Others |
| CIOC | Central Illinois Orthopaedic Center
| Others |
| CIOC | Chief Information Officer Committee
| Others |
| CIOC | Chief Information Officer Council
| Others |
| CIOC | Chief Information Officers Council
| Others |
| CIOC | Citizens Infrastructure Oversight Commission
| Others |
| CIOC | Comet ISON Observing Campaign
| Others |
| CIOC | Command Intelligence Operations Center
| Others |
| CIOC | Community Information Online Consortium
| Others |
| CIOC | Conferencia Internacional de Organismos de Cuenca
| Others |
| CIOC | Counterinsurgency Operations Command
| Others |