RPI is an abbreviation for
- Raspberry Pi, a single-board computer developed in the UK by the Raspberry Pi Foundation
- Ratings Percentage Index, the NCAA ranking system (most well known for its use in basketball)
- Recognition Professionals International
- Rensselaer Polytechnic Institute, a university in Troy, New York
- Republican Party of India
- Republican Party of Iowa
- Retail Prices Index (United Kingdom), a statistical measurement of inflation
- Reticulocyte production index or Reticulocyte index
- Revenue Protection Inspector, the United Kingdom public transit patrol
- Richmond Professional Institute, former college before being merged with MCV into Virginia Commonwealth University
- Rock progressivo Italiano or Italian progressive rock
- Roleplay Intensive MUD, or RPIMUD, a category of MUD defined by enforcement of roleplay and computer-modeled game world
- Rose Polytechnic Institute, an older name for Rose-Hulman Institute of Technology, a college in Terre Haute, Indiana
- Ryerson Polytechnic Institute, an older name for Ryerson University, a university in Toronto, Ontario.