| IRAS | Implementation Of Readac Automated Systems 
| Others |
| IRAS | Independent Radiation Assessment Services
| Others |
| IRAS | Indian Railway Accounts Service
| Others |
| IRAS | Individual Retirement Accounts share
| Others |
| IRAS | Infra Red Astronomical Satellite
| Others |
| IRAS | Infra Red Source
| Others |
| IRAS | Infrared Reflection Absorption Spectroscopy
| Others |
| IRAS | Infrared Reflection-Absorption Spectroscopy
| Others |
| IRAS | Inland Revenue Authority of Singapore
| Others |
| IRAS | Inspector Recruitment Application System
| Others |
| IRAS | Institute for Risk Assessment Sciences
| Others |
| IRAS | Institute on Religion in an Age of Science
| Others |
| IRAS | Integrated Research Application System
| Others |
| IRAS | Integrated Research Approval System
| Others |
| IRAS | Internet Routing and Access Service
| Others |
| IRAS | IPsec Remote Access Server
| Others |
| IRAS | Retirement Accounts and Small
| Others |