| Acronym | Definition |
|---|
| RIS | Radiology Information System |
| RIS | Remote Installation Service (Microsoft Windows 2000) |
| RIS | Regulatory Impact Statement |
| RIS | River Information Services |
| RIS | Regional Innovation Strategy (European Commission) |
| RIS | Robotics Invention System (LEGO) |
| RIS | Regulatory Information Service |
| RIS | Russian Imperial Stout |
| RIS | Rail Interface System |
| RIS | Rail Interface System (accessory mount on guns) |
| RIS | Review of Information Science |
| RIS | Resonance Ionization Spectroscopy |
| RIS | Retroreflector In Space |
| RIS | Retail Information Systems |
| RIS | Reviving the Islamic Spirit (conference) |
| RIS | Redwood Inspection Service |
| RIS | Random Interleaved Sampling |
| RIS | Retirement Income Specialist |
| RIS | Reparti Investigazioni Scientifiche (Italy, Carabinieri) |
| RIS | Request for Information Services |
| RIS | Raumbezogenes Informationssystem (German: Spacereferred information systems) |
| RIS | Range Instrumentation System |
| RIS | Rothberg International School (Hebrew University of Jerusalem, Israel) |
| RIS | Radio Investigation Service |
| RIS | Retirement and Insurance Service (a component of OPM) |
| RIS | Radar Integration System |
| RIS | Roosevelt Intermediate School (Westfield, NJ) |
| RIS | Recreation and Intramural Sports |
| RIS | Relocation Information Services |
| RIS | Radar Interrogator Set (associated with joint surveillance system) |
| RIS | Readiness Information System |
| RIS | Ridgecrest Intermediate School |
| RIS | Reinforced Insulated Sheath (Star Wars armor) |
| RIS | Research Investment Strategy (Australia) |
| RIS | Representative Indicator Species (US EPA) |
| RIS | Received in Swap |
| RIS | Romulan Imperial Ship (Star Trek) |
| RIS | Restricted Instructional Setting |
| RIS | Redundant Information Sector (COMPAQ) |
| RIS | Report/ing Identification Symbol |