| Acronym | Definition |
|---|
| RIS | Radiology Information System |
| RIS | Regulatory Impact Statement |
| RIS | Republik Indonesia Serikat (Indonesian: Republic of Indonesia) |
| RIS | Remote Installation Service (Microsoft Windows 2000) |
| RIS | Release in Specific (US DoD) |
| RIS | Refugee and Immigration Services (various locations) |
| RIS | Ruamrudee International School (Thailand) |
| RIS | Radio Interference Suppression |
| RIS | River Information Services |
| RIS | Raads Informatie Systeem (Dutch: Wire Information System) |
| RIS | Research and Information System (India) |
| RIS | Reduced Instruction Set |
| RIS | Remote Installation Server |
| RIS | Raster Image Set |
| RIS | Research and Instructional Support |
| RIS | Recoverable in-Doubt Structure |
| RIS | Radio Information Service |
| RIS | Retail Information System |
| RIS | Remote Installation Service |
| RIS | Regulatory Issue Summary (various organizations) |
| RIS | Robotics Invention System (LEGO) |
| RIS | Reviving the Islamic Spirit (conference) |
| RIS | Ramsar Information Sheet (Ramsar Convention on Wetlands) |
| RIS | Raba Interneta v Sloveniji (Slovenian: Internet Research in Slovenia) |
| RIS | Rail Interface System |
| RIS | Russian Imperial Stout |
| RIS | Rainbow International School (Seoul, South Korea) |
| RIS | Regulatory Information Service |
| RIS | Regional Innovation Strategy (European Commission) |
| RIS | Research and Instructional Support (various schools) |
| RIS | Retail Information Systems |
| RIS | Rail Interface System (accessory mount on guns) |
| RIS | Review of Information Science |
| RIS | Research Innovation Services (UK) |
| RIS | Resonance Ionization Spectroscopy |
| RIS | Retroreflector In Space |
| RIS | Remote Information Service |
| RIS | Rothberg International School (Hebrew University of Jerusalem, Israel) |
| RIS | Redwood Inspection Service |
| RIS | Random Interleaved Sampling |
| RIS | Retirement Income Specialist |
| RIS | Reparti Investigazioni Scientifiche (Italy, Carabinieri) |
| RIS | Request for Information Services |
| RIS | Range Instrumentation System |
| RIS | Research Investment Strategy (Australia) |
| RIS | Raumbezogenes Informationssystem (German: Spacereferred information systems) |
| RIS | Rich Internet Solutions (Netherlands) |
| RIS | Retirement and Insurance Service (a component of OPM) |
| RIS | Radio Investigation Service |
| RIS | Roosevelt Intermediate School (Westfield, NJ) |
| RIS | Recreation and Intramural Sports |
| RIS | Rannsóknagagnasafn Íslands (Icelandic: Research Bank; database) |
| RIS | Radar Integration System |
| RIS | Relocation Information Services |
| RIS | Readiness Information System |
| RIS | Ridgecrest Intermediate School |
| RIS | Reinforced Insulated Sheath (Star Wars armor) |
| RIS | Representative Indicator Species (US EPA) |
| RIS | Received in Swap |
| RIS | Robotique et Interactions (French: Robotics and Interactions; research group) |
| RIS | Romulan Imperial Ship (Star Trek) |
| RIS | Restricted Instructional Setting |
| RIS | Redundant Information Sector (COMPAQ) |
| RIS | Radar Interrogator Set (associated with joint surveillance system) |
| RIS | Report/ing Identification Symbol |
| RIS | Regulatory Information Specialist (US FDA) |