| 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) |