Oi

Oi may refer to:

• Oi (shogi) (Ōi), one of the seven titles of Japanese professional shogi (board game) tournament
• Japanese cruiser Ōi, a WWII era Japanese warship
• Ōi, other name for Japanese artist Sakae, the youngest daughter of Hokusai.
• Oi (telecommunications), the largest landline telephone company in Brazil
• Oi (digraph), a digraph used in various languages
• Great-winged Petrel, also known by its Māori name oi
• Oi (interjection), a British interjection used to get someone's attention, or to express surprise or disapproval
• Oi!, a subgenre of punk rock
• "Oi!", a 2002 hit song for British grime crew More Fire Crew
• Aussie Aussie Aussie, Oi Oi Oi
• Mark "Jacko" Jackson, a former Australian rules football playerer, catchphrase "Oi!"
• Katsushika Ōi, a Japanese painter and print artist and daughter of Katsushika Hokusai
• Oi Oi Oi (album), an album by Boys Noize
• Oi!, a Portuguese language interjection

OI may refer to:

• Owens-Illinois, a Fortune 500 company, a S&P 500 company
• OpenIndiana, a fork (of sorts) of the OpenSolaris operating system
• Optical illusion
• Orthostatic intolerance, a disorder of the autonomic nervous system
• Osteogenesis imperfecta, a genetic bone disorder
• Oriental Institute (disambiguation)
• Orphans International, a global charitable organization the benefits orphans and abandoned children
• Oratorical Interpretation, a forensics category
• gha, a letter, misnamed by the ISO as "LATIN LETTER OI", typographically based on Q
• O-I, a Japanese tank design of the Second World War
• Olympiad in Informatics, or International Olympiad in Informatics, an international programming competition for high school students
• Organizational Intelligence
• Operational Intelligence, a form of real-time dynamic, business analytics that delivers visibility and insight into business operations.
• Oxygen Index, the ratio oxygen:carbon used in Van Krevelen diagrams by petroleum geologists for the assessment of kerogen maturity