HVO may refer to:
Organizations Croatian Defence Council (Croatian: ), the main military force of Croats of Bosnia and Herzegovina during the Bosnian War Hawaiian Volcano Observatory Health Volunteers Overseas, an American nonprofit organization Hidden Valley Observatory, in South Dakota, United States Hindu Volunteers' Organisation
Sports HC Vítkovice Ostrava, an ice hockey club in Ostrava, Czech Republic Heritage Village Open, a former LPGA golf tournament Hermes Volley Oostende, a volleyball team in Oostende, Belgium
Other uses Hydrotreated vegetable oil, biofuel made by hydrogenating vegetable or animal fat Volda University College (Norwegian: )