HOI or Hoi may refer to:
Home insurance, or homeowners insurance (HOI) Hypoiodous acid, chemical formula HOI Carsten Høi (born 1957), Danish chess Grandmaster
Places Hoi District, Aichi, Japan Hao Airport, French Polynesia, IATA code HOI
Video games Hoi (video game), 1992 Hearts of Iron (HOI) a grand strategy video game series by Paradox Development Studio Hearts of Iron (HOI), a 2002 video game and the first entry in the eponymous video game series Hearts of Iron II (HOI2), a 2005 video game Hearts of Iron III (HOI3), a 2009 video game Hearts of Iron IV (HOI4), a 2016 video game and the latest entry in the series
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)