WPI may refer to:
Organizations
- Whittemore Peterson Institute, performs research into chronic fatigue syndrome
- Worcester Polytechnic Institute, a private research university in Worcester, Massachusetts, US
- Worker-communist Party of Iran, a political party
Other uses
- Whey protein isolate, a dietary supplement created by filtering milk protein
- Wholesale price index, the price of a representative basket of wholesale goods
- Work Personality Index, a psychometric assessment
- Wraps per inch, a measure of thickness of yarn
See also
- Derwent World Patents Index (DWPI)