HWI may refer to:
- Hauptman-Woodward Medical Research Institute, in Buffalo, New York, United States
- Healthware International, an Italian advertising company
- High water interval, or lunitidal interval, of tides
- Horwich Parkway railway station, England
- Humanity World International
- Wismar, Germany, vehicle registration code
- Hardware Wholesalers, Inc., now Do It Best, an American hardware retailer