| Input/output Supervision | Space Science | IOS |
| Indian Ocean Ship, Spaceflight Tracking Data Network Station | Space Science | IOS |
| Intellegent Operating System | Computer Technology | IOS |
| iPhone/iPad/iPod Operating System | Software | IOS |
| iPhone Operating System | Computer Software | IOS |
| instructor/operator station | Government | IOS |
| Intelligent Operating Software | Softwares | IOS |
| Institute of Oceanographic Sciences | Ocean Science | IOS |
| input-output selector | Government | IOS |
| interim operational supplement | Government | IOS |
| Institute of Ocean Sciences | Ocean Science | IOS |
| International Online Soccer | Sports | IOS |
| Internetwork Operating System | Networking | IOS |
| integrated observation system | Government | IOS |
| Internetworking Operating System (cisco) | Networking | IOS |
| Indian Ocean Station | Space Science | IOS |
| Instructor Operator Station | Space Science | IOS |
| Internet Over Satellite | Telecommunication | IOS |
| Inter-Operability Specifications | Computer and Networking | IOS |
| Ilheus | Airport Code | IOS |
| Investment Opportunity Set | Stock Exchange | IOS |
| Inspection Operation System | Banking | IOS |
| International Organization for Standardization | Business | IOS |
| Ilheus airport | Regional Airport Code | IOS |
| Input Output System | Computing | IOS |
| International Outsourcing Services | International Business | IOS |
| Internal Operating System | Softwares | IOS |
| Independent On Sunday | Other | IOS |
| Internet Operating System | Computer Networking | IOS |
