IRS (disambiguation)
- Chinese Democracy
- I.R.S. Records
- IR$
- IRS
- IRS Aero
- IRS Airlines
- Independence Republic of Sardinia
- Indian Readership Survey
- Indian Remote Sensing satellite
- Indian Revenue Service
- Indoor residual spraying
- Inertial reference system
- Institutionalized Riot Systems
- Insulin receptor substrate
- Insulin receptor substrate 1
- Insulin receptor substrate 2
- Integrated reception system
- Interest rate swap
- Intergroup Rhabdomyosarcoma Study Group
- Internal Revenue Service (Ghana)
- International Railway Systems
- International Rules Series
- International Union of Railways
- Kirsch Municipal Airport
- Leibniz Association
- Mike Rotunda
- Taxation in Portugal