HOI or Hoi may refer to:
- Home insurance, or homeowners insurance (HOI)
- Hypoiodous acid, chemical formula HOI
- Hoi District, Aichi, Japan
- Carsten Høi (born 1957), Danish chess Grandmaster
- Hao Airport, French Polynesia, IATA code HOI
- Hoi (video game), 1992
See also
- H0i, or H0f, a rail transport modelling scale
- HO-1 (disambiguation), including HO1
- H1 (disambiguation), including H01
- Hoe (food), various Korean raw fish dishes
- Hoi polloi
- Holl, a surname
- Oi (interjection)