CSIO
| Acronym | Definition |
|---|---|
| CSIO | Central Scientific Instruments Organisation |
| CSIO | Concours de Saut International Officiel (French: International Jumping Competition Official; equestrianism) |
| CSIO | Centre for Studies in Insurance Operations (Canada) |
| CSIO | Chief Security Information Officer |
| CSIO | Clock-Synchronous Serial IO |
| CSIO | Combat Systems Information Officer (US Navy) |