are ogres or demons in Japanese folklore.

Oni may also refer to:

• Oni (band), a Canadian progressive metal band

• Oni Press, an independent comic book publisher

• Ooni, the kings of Nigeria's Yoruba people

• Oni–Adil, Indian composer duo

• Miye Oni (born 1997), American basketball player

• Oni Gozen, a Japanese female warrior from the 16th century

• Oni, Maharashtra, a small village in Western India

• Oni, Georgia, a town in Georgia

• Oni (letter), the 16th letter of the three Georgian scripts

• Oni: Thunder God's Tale, stop-motion series

• Oni (video game), a 2001 third-person action video game made by Bungie

• Adesuwa Oni (born 1989), British actress

• Onimusha, a series of action video games made by Capcom

• Oni Aliens, foes in the Gantz manga

• Oni, the title of an unfinished Akira Kurosawa script that was later adapted to a video game named Nioh

• Oni, a race of aliens from the manga and anime Urusei Yatsura

• The Oni, a primary antagonist in seasons 8-10 of the TV series Ninjago

• Oni (Street Fighter), an alternate form of Akuma that appears in the Super Street Fighter IV: Arcade Edition video game

• Oni, an antagonist in the Mortal Kombat: Shaolin Monks video game

• My Oni Girl, a 2024 anime film by Studio Colorido

ONI may refer to:

• Office of Naval Intelligence, the United States Navy's intelligence agency

• Office of National Intelligence, an Australian government intelligence agency

• OpenNet Initiative, a project for tracking the use of Internet filtering and surveillance

• ONI Systems Corporation, an optical networking company acquired by Ciena Corporation in 2002

• ONI (Oxford Nanoimaging), a super-resolution microscope company

• Oxygen Not Included, a simulation video game by Klei Entertainment

• OASIS Neural Interface, a VR technology system used in Ready Player Two

• Oceanic Niño Index, the numerical metric for El Niño used by the U. S government's NOAA