| Acronym | Definition |
|---|
| CASO | Communauté d'Agglomération de Saint-Omer (French: Agglomeration Community of Saint-Omer; Saint-Omer, France) |
| CASO | Central Aichi Symphony Orchestra (Japan) |
| CASO | Computer Animation Studios of Ontario (Toronto, Ontario, Canada) |
| CASO | Central Administration Server Option (server management program) |
| CASO | Canada Southern Railway Company |
| CASO | Cancellation Addendum Sales Order (NASA) |
| CASO | Chief Aviation Security Officer (various locations) |
| CASO | Computer Resources Acquisition Support Office |
| CASO | Centre d'Accueil, d'Orientation et de Soins (French: Welcome, Care and Guidance Center; Doctors of the World) |