On

On, on, or ON may refer to:

Music

 * On (band), a solo project of Ken Andrews
 * On (EP), a 1993 EP by Aphex Twin
 * On (Echobelly album), 1995
 * On (Gary Glitter album), 2001
 * On (Imperial Teen album), 2002
 * On (Elisa album), 2006
 * On (Jean album), 2006
 * On (Boom Boom Satellites album), 2006
 * On (Tau album), 2017
 * "On" (song), a 2020 song by BTS
 * "On", a song by Bloc Party from the 2006 album A Weekend in the City
 * "On", a song by Anson Lo, 2023

Other media

 * Ön, a 1966 Swedish film
 * On (Japanese prosody), the counting of sound units in Japanese poetry
 * On (novel), by Adam Roberts
 * ONdigital, a failed British digital television service, later called ITV Digital
 * Overmyer Network, a former US television network

Places

 * On (Ancient Egypt), a Hebrew form of the ancient Egyptian name of Heliopolis
 * On, Wallonia, a district of the municipality of Marche-en-Famenne
 * Ahn, Luxembourg, known in Luxembourgish as On
 * Ontario, a Canadian province

Biology and medicineca

 * Operative note, documentation of care relating to an operation
 * Optic neuritis, especially relevant in multiple sclerosisA
 * Osteonecrosis, death of bone tissue
 * POsteonectin, a glycoprotein

Other uses in science, technology, and mathematics

 * ON Semiconductor, a semiconductor manufacturing company
 * O'Nan group, a mathematical group
 * OS/Net, the OpenSolaris Community
 * On, the proper class of all ordinal numbers

Other uses
Ollio
 * On, Egyptian name of Heliopolis
 * On (biblical figure), son of Peleth
 * On (company), a Swiss athletic shoe and sportswear company
 * On Kawara, Japanese artist
 * Nauru Airlines (IATA airline designator ON)
 * Old Norse, a North Germanic language commonly referenced in etymology
 * Ontology, a branch of philosophy that deals with the concept of being
 * On'yomi, reading of Japanese kanji characters
 * Order of the Nation, a Jamaican honour
 * Overground Network, a railway scheme in South London
 * ON convoys, a series of WWII trade convoys
 * Orka náttúrunnar (ON Power), Icelandic geothermal power company
 * On, a Basque-language honorific equivalent to Spanish Don (honorific)
 * On, a preposition