| Acronym | Definition |
|---|
| CISO | Chief Information Security Officer |
| CISO | California Independent System Operator |
| CISO | Counterintelligence Support Officer (US DoD) |
| CISO | Corporate Information Security Officer (corporate position) |
| CISO | Counterintelligence Staff Officer (US DoD) |
| CISO | Canadian International Security Organization (Captain Canuck comic fictional spy organization) |
| CISO | Centro de Investigacion y Solidaridad Obrera (Spanish: Research Center and Working Solidarity; Mexico) |
| CISO | Counterintelligence Security Officer |
| CISO | Curriculum Instructions & Standards Office |
| CISO | Commercial Imagery Staff Office |