O is the fifteenth letter of the modern Latin alphabet. O may also refer to:

Letters

* Օ օ, (Unicode: U+0555, U+0585) a letter in the

Armenian alphabet The Armenian alphabet ( hy, Հայոց գրեր, ' or , ') is an alphabetic writing system used to write Armenian. It was developed around 405 AD by Mesrop Mashtots, an Armenian linguist and ecclesiastical leader. The system originally had ...

* Ο ο,

Omicron Omicron (; uppercase Ο, lowercase ο, ell, όμικρον) is the 15th letter of the Greek alphabet. This letter is derived from the Phoenician letter ayin: . In classical Greek, omicron represented the close-mid back rounded vowel in cont ...

, (Greek), a letter in the Greek alphabet *

O (Cyrillic) O (О о; italics: ) is a letter of the Cyrillic script. O commonly represents the close-mid back rounded vowel , like the pronunciation of in Scottish English "go". History The Cyrillic letter O was derived from the Greek letter Omicron ...

, a letter of the Cyrillic alphabet *

O (kana) In Japanese writing, the kana お (hiragana) and オ (katakana) occupy the fifth place, between え and か, in the modern Gojūon (五十音) system of collating kana. In the Iroha, they occupy the 27th, between の and く. In the table ...

, a romanization of the kana (お and オ) in Japanese writing * ㅇ, a consonant in Hangul, the Korean alphabet * ဝ, a consonant in Burmese script * /o/, close-mid back rounded vowel in the International Phonetic Alphabet Vo (letter)

Arts and entertainment

Film and television

* ''O'' (film), 2001 film starring Josh Hartnett, Mekhi Phifer and Julia Stiles

Literature

* '' O: A Presidential Novel'', anonymous novel published in 2011 * O, fictional planet that is the setting of several short stories by science fiction author Ursula K. Le Guin * O, fictional character from the French erotic novel '' Story of O'' * '' "O" Is for Outlaw'', the fifteenth novel in Sue Grafton's "Alphabet mystery" series, published in 1999

Media and publications

* ''

O, The Oprah Magazine ''O, The Oprah Magazine'', also known simply as ''O'', is an American monthly magazine founded by talk show host Oprah Winfrey and Hearst Communications. Overview It was first published on April 19, 2000. , its average paid circulation was ...

'', magazine founded by Oprah Winfrey * '' «O»'', an international fetish magazine

Music

* " O (Oh!)", 1920 by Ted Lewis, 1953 by Pee Wee Hunt * ''O'' (A.C. Acoustics album), 2002 * ''O'' (Damien Rice album), 2002 * ''O'' (Eiko Shimamiya album), 2006 * ''O'' (Omarion album), 2005 ** "O" (Omarion song), the title song * ''o'' (Tilly and the Wall album), 2008 * ''O'', 2002 album by

Zone Zone or The Zone may refer to: Places Climate and altitude zones * Death zone (originally the lethal zone), altitudes above a certain point where the amount of oxygen is insufficient to sustain human life for an extended time span * Frigid zone, ...

* "O", a 2014 song by Coldplay from '' Ghost Stories'' * "o", a song by

iamamiwhoami iamamiwhoami ( ) is the electronic music and audiovisual project of Swedish singer-songwriter Jonna Lee in collaboration with her longtime record producer Claes Björklund. The project has, since 2009, released audiovisual series on their ch ...

* "O!", a song by the American band Bright from ''

The Albatross Guest House ''The Albatross Guest House'' is the second studio album by Bright. It came out as a split release CD on Darla Records (catalog #DRL-044) and Ba-Da-Bing! Records (catalog #BING-010) in 1997. Track listing All songs written by Bright #"You Nee ...

'', 1997

Sports

O (gesture) The "O" is a gesture used predominantly at the University of Oregon (UO) in Eugene, Oregon, United States, and especially at events in which the school's athletic teams, the Oregon Ducks, are taking part. The gesture is used to show support for th ...

, a gesture used to show support for the sports teams of the University of Oregon *

Baltimore Orioles The Baltimore Orioles are an American professional baseball team based in Baltimore. The Orioles compete in Major League Baseball (MLB) as a member club of the American League (AL) East division. As one of the American League's eight char ...

, an American Major League Baseball team, among whose common nicknames are "O's" and "The O's"

Others

* ''O'' (Cirque du Soleil), show at the Bellagio hotel and casino in Las Vegas, Nevada

Companies

* Essie's Original Hot Dog shop (commonly known as "The O"), a restaurant in Pittsburgh, Pennsylvania *

Overstock.com Overstock.com, Inc. is an American internet retailer selling primarily furniture headquartered in Midvale, Utah, near Salt Lake City. Businessman Patrick M. Byrne founded Overstock.com in 1999. The company initially sold exclusively surplus an ...

, online retailer previously known as O.co *

Realty Income Realty Income Corporation is a real estate investment trust that invests in free-standing, single-tenant commercial properties in the United States, Spain and the United Kingdom that are subject to NNN Leases. The company is organized in Marylan ...

, American real estate investment trust (NYSE stock ticker O)

History

O-class battlecruiser The O class was a planned class of three battlecruisers for the ''Kriegsmarine'' (German navy) before World War II. Prompted by a perceived lack in ship numbers when compared with the British Royal Navy, the O class' design was born with the sug ...

, class of German ships in the 1930s *

The O (political group) The O., short for "the Organization", also known as the C.O. or Coop Organization, was a Black-led radical political cadre organization that grew out of the Twin Cities New Left movement in the 1970s. It was established in 1974 by Theophilus Smith, ...

(The Organization), a 1970s American political group

Linguistics

* O, an antiquated

vocative In grammar, the vocative case (abbreviated ) is a grammatical case which is used for a noun that identifies a person (animal, object, etc.) being addressed, or occasionally for the noun modifiers ( determiners, adjectives, participles, and n ...

placed before a name of, or phrase characterizing, the party being addressed * O (also P), the patient-like argument (object) of a canonical transitive verb *O, gender neutral third person pronoun in the Turkish language

Mathematics

f = O(g)

, a Bachmann–Landau notation in computational complexity theory (", ''f'', is bounded above by ''g'' asymptotically") *

f = o(g)

, a Bachmann–Landau notation in computational complexity theory ("''f'' is dominated by ''g'' asymptotically") * O, for

orthogonal group In mathematics, the orthogonal group in dimension , denoted , is the group of distance-preserving transformations of a Euclidean space of dimension that preserve a fixed point, where the group operation is given by composing transformations. ...

* ∘ indicates

function composition In mathematics, function composition is an operation that takes two functions and , and produces a function such that . In this operation, the function is applied to the result of applying the function to . That is, the functions and ...

, or composition of morphisms in a category *

Category O In the representation theory of semisimple Lie algebras, Category O (or category \mathcal) is a category whose objects are certain representations of a semisimple Lie algebra and morphisms are homomorphisms of representations. Introduction As ...

\mathcal

, a category of Lie algebra representations * o, for

octet Octet may refer to: Music * Octet (music), ensemble consisting of eight instruments or voices, or composition written for such an ensemble ** String octet, a piece of music written for eight string instruments *** Octet (Mendelssohn), 1825 com ...

, an information measure unit used in computing

Media

* O, an

IRC operator An IRC operator (often abbreviated as IRCop or oper) is a user on an Internet Relay Chat network who has privileged access. IRC operators are charged with the task of enforcing the network's rules, and in many cases, improving the network in vari ...

service in QuakeNet's IRC services

Places

* O Brook, a short river in Devon, England

Science

Oxygen Oxygen is the chemical element with the symbol O and atomic number 8. It is a member of the chalcogen group in the periodic table, a highly reactive nonmetal, and an oxidizing agent that readily forms oxides with most elements as well ...

, symbol O, a chemical element * O, a human

blood type A blood type (also known as a blood group) is a classification of blood, based on the presence and absence of antibodies and inherited antigenic substances on the surface of red blood cells (RBCs). These antigens may be proteins, carbohydra ...

, the universal donor *

Haplogroup O (Y-DNA) Haplogroup O, also known as O-M175, is a human Y-chromosome DNA haplogroup. It is primarily found among populations in Southeast Asia and East Asia. It also is found in various percentages of populations of the Russian Far East, South Asia, Centr ...

, a Y-chromosomal DNA haplogroup * O, for

pyrrolysine Pyrrolysine (symbol Pyl or O; encoded by the 'amber' stop codon UAG) is an α-amino acid that is used in the biosynthesis of proteins in some methanogenic archaea and bacteria; it is not present in humans. It contains an α-amino group (which ...

an alpha amino acid in biochemistry * Class O, stellar classification for very hot bluish stars * O (for ''Octavius'', meaning an eight of a gallon), an apothecary's symbol for a

pint The pint (, ; symbol pt, sometimes abbreviated as ''p'') is a unit of volume or capacity in both the imperial and United States customary measurement systems. In both of those systems it is traditionally one eighth of a gallon. The British imp ...

Surname

O (surname) O or Oh is a family name in Korea. It is written using the hanja characters, 吳, 五, 伍, 吾, and 晤. According to the 2015 census in South Korea, there were 763,281 people carrying the O surname. History O also spelled Oh (Hangul: ) is th ...

, Korean surname romanized "O" or "Oh" * Ō (Japanese surname), Japanese surname derived from the Chinese surname Wang (王) *

Ou (surname) Ou is the pinyin romanization of the Chinese surnames and , which share a common origin with the compound surname Ouyang (), from the ruling family of the State of Yue during the Spring and Autumn period. They are commonly romanized as Au or Ao i ...

, Chinese and Cantonese surnames pronounced "O" or "Oh" * A prefix meaning "grandson (of)", appearing in

Irish surnames A formal Irish name consists of a given name and a surname. In the Irish language, surnames are generally patronymic in etymology but are no longer literal patronyms as, for example, most Icelandic names still are. The form of a surname varies ac ...

* Genovevo de la O (1876-1952), Mexican revolutionary *

Karen O Karen Lee Orzolek (born November 22, 1978) is a South Korean-born American singer, musician, and songwriter. She is the lead vocalist for the indie rock band Yeah Yeah Yeahs. Early life She was born in Seoul, South Korea, the daughter of a Ko ...

, born Karen Lee Orzolek, American singer

Other uses

* Oreo O's, an American breakfast cereal available internationally * Oscar, the military time zone code for UTC−02:00: List of military time zones#O