O, or o, is the fifteenth Letter (alphabet), letter in the ISO basic Latin alphabet and the fourth vowel letter in the English alphabet, modern English alphabet. Its name in English is English alphabet#Letter names, ''o'' (pronounced ), plural English alphabet#Letter names, ''oes''.


or early Baroque design of an O, from 1627 Its graphic form has remained fairly constant from Phoenician alphabet, Phoenician times until today. The name of the Phoenician alphabet, Phoenician letter was ''Ayin, ʿeyn'', meaning "eye", and indeed its shape originates simply as a drawing of a human eye (possibly inspired by the corresponding Egyptian hieroglyphs, Egyptian hieroglyph, cf. Proto-Sinaitic script). Its original sound value was that of a consonant, probably , the sound is represented by the cognate Arabic alphabet, Arabic letter ع, ع ''ʿayn''. The use of this Phoenician letter for a vowel sound is due to the early Greek alphabets, which adopted the letter as Omicron, O "omicron" to represent the vowel . The letter was adopted with this value in the Old Italic alphabets, including the early Latin alphabet. In Greek, a variation of the form later came to distinguish this long sound (Omega, meaning "large O") from the short o (Omicron, meaning "small o"). Greek omicron gave rise to the corresponding O (Cyrillic), Cyrillic letter O and the early Italic letter to Odal (rune), runic ᛟ. Even alphabets that are not derived from Semitic tend to have similar forms to represent this sound; for example, the creators of the Afaka script, Afaka and Ol Chiki scripts, each invented in different parts of the world in the last century, both attributed their vowels for 'O' to the shape of the mouth when making this sound.

Use in writing systems


The letter is the fourth Letter frequency, most common letter in the English alphabet. Like the other English vowel letters, it has associated "long" and "short" pronunciations. The "long" as in ''boat'' is actually most often a diphthong (realized dialectically anywhere from to ). In English there is also a "short" as in ''fox'', , which sounds slightly different in different dialects. In most dialects of British English, it is either an open-mid back rounded vowel or an open back rounded vowel ; in American English, it is most commonly an unrounded back to a central vowel . Common Digraph (orthography), digraphs include , which represents either or ; or , which typically represents the diphthong , and , , and which represent a variety of pronunciations depending on context and etymology. In other contexts, especially before a letter with a minim (palaeography), minim, may represent the sound , as in 'son' or 'love'. It can also represent the semivowel as in ''choir'' or ''quinoa.'' In English, the letter in isolation before a noun, usually capitalized, marks the vocative case, as in the titles to O Canada or O Captain! My Captain! or certain verses of the Bible.

Other languages

File:Pronunciation of the name of the letter ⟨o⟩ in European languages.png, Pronunciation of the name of the letter in European languages, 305x305px, left is commonly associated with the open-mid back rounded vowel , mid back rounded vowel or close-mid back rounded vowel in many languages. Other languages use for various values, usually back vowels which are at least partly open. Derived letters such as and have been created for the alphabets of some languages to distinguish values that were not present in Latin and Greek, particularly rounded front vowels.

Other systems

In the International Phonetic Alphabet, represents the close-mid back rounded vowel.

Related characters

Descendants and related characters in the Latin alphabet

Derived signs, symbols and abbreviations

* Ꝋ ꝋ : Forms of O were used for medieval scribal abbreviations *∅ : Empty set, empty set symbol *º : Masculine ordinal indicator

Ancestors and siblings in other alphabets

*𐤏 : Phoenician alphabet, Semitic letter Ayin, from which the following symbols originally derive **Ο ο : Greek alphabet, Greek letter Omicron *** : Coptic alphabet, Coptic letter O, which derives from Greek omicron ***О о : Cyrillic letter O (Cyrillic), O, which also derives from Omicron ***𐌏 : Old Italic script, Old Italic O, which derives from Greek Omicron, and is the ancestor of modern Latin O ***Օ օ : Armenian alphabet, Armenian letter O

Computing codes

: 1

Other representations

See also

*Oxygen = O *O mark *Open O (Ɔ ɔ)


External links

* {{Latin alphabet, O} ISO basic Latin letters Vowel letters