O (О о; italics: О о) is a letter of the Cyrillic script.

Quick Facts Cyrillic letter O, Phonetic usage: ...

Cyrillic letter O
Phonetic usage:	[o], [ɔ], [ɐ], [ɒ], [ʌ]
Numeric value:	70
Derived from:	Greek letter Omicron (Ο ο)
The Cyrillic script
Slavic letters
А А̀ А̂ А̄ Ӓ Б В Г Ґ Д Ђ Ѓ Е Ѐ Е̄ Е̂ Ё Є Ж З З́ Ѕ И І Ї Ꙇ Ѝ И̂ Ӣ Й Ј К Л Љ М Н Њ О О̀ О̂ Ō Ӧ П Р С С́ Т Ћ Ќ У У̀ У̂ Ӯ Ў Ӱ Ф Х Ц Ч Џ Ш Щ Ꙏ Ъ Ъ̀ Ы Ь Ѣ Э Ю Ю̀ Я Я̀
Non-Slavic letters
Ӑ А̊ А̃ Ӓ̄ Ӕ Ә Ә́ Ә̃ Ӛ В̌ Ԝ Г̑ Г̇ Г̣ Г̌ Г̂ Г̆ Г̈ Ҕ Ғ Ӻ Ғ̌ Ӷ Д́ Д̌ Д̈ Д̣ Д̆ Ӗ Е̃ Ё̄ Є̈ Ԑ Ԑ̈ Җ Ӝ Ӂ Ж̣ Ҙ Ӟ З̌ З̣ З̆ Ӡ И̃ Ӥ Ҋ Қ Ӄ Ҡ Ҟ Ҝ К̣ Ԛ ᴫ Л́ Ӆ Ԯ Ԓ Л̈ Ӎ ᵸ Н́ Ӊ Ң Ԩ Ӈ Ҥ О̆ О̃ Ӧ̄ Ө Ө̄ Ө́ Ө̆ Ӫ Ԥ П̈ Ҏ Р̌ С̌ Ҫ С̣ С̱ Т́ Т̈ Т̌ Т̇ Т̣ Ҭ У̃ Ӳ У̊ Ӱ̄ Ұ Ү Ү́ Х̣ Х̱ Х̮ Х̑ Х̌ Ҳ Ӽ Ӿ Һ Һ̈ Ԧ Ц̌ Ц̈ Ҵ Ҷ Ҷ̣ Ӵ Ӌ Ҹ Ч̇ Ч̣ Ҽ Ҿ Ш̈ Ш̣ ꚜ Ы̆ Ы̄ Ӹ ꚝ Ҍ Ҩ Э̆ Э̄ Э̇ Ӭ Ӭ́ Ӭ̄ Ю̆ Ю̈ Ю̄ Я̆ Я̄ Я̈ Ӏ ʼ ˮ
Archaic or unused letters
А̨ Б̀ Б̣ Б̱ В̀ Г̀ Г̧ Г̄ Г̓ Г̆ Ҕ̀ Ҕ̆ Ԁ Д̓ Д̀ Д̨ Ԃ Ꚁ Ꙣ Е̇ Е̨ Ж̀ Ж̑ Ꙃ Ꙅ Џ̆ Ꚅ Ꚅ̆ Ꙁ З̀ З̑ Ԅ Ԇ Ꚉ Ԫ Ꚃ Ꚕ І̂ І̣ І̨ Ј̵ Ј̃ Ꙉ К̓ К̀ К̆ Ӄ̆ К̑ К̇ К̈ К̄ Ԟ К̂ Л̀ Ԡ Ꙥ Ԉ Л̑ Л̇ Ԕ М̀ М̃ Ꙧ Н̀ Н̄ Н̧ Н̃ Ԋ Ԣ Н̡ Ѻ Ꙩ Ꙫ Ꙭ ꙮ Ꚙ Ꚛ П̓ П̀ П́ Ҧ П̧ П̑ Ҁ Ԛ̆ Р́ Р̀ Р̃ Ԗ С̀ С̈ Ԍ Ҫ̓ Т̓ Т̀ Ԏ Т̑ Ꚋ Т̧ Ꚍ Ꚍ̆ ОУ Ꙋ У̇ У̨ ꙋ́ Ф̑ Ф̓ Х́ Х̀ Х̆ Х̇ Х̧ Х̾ Х̓ һ̱ Ѡ Ꙍ Ѽ Ѿ Ꙡ Ц̀ Ц́ Ц̓ Ꚏ Ꚏ̆ Ꚑ Ч́ Ч̀ Ч̆ Ч̑ Ч̓ Ԭ Ꚓ Ꚇ Ꚇ̆ Ҽ̆ Ш̀ Ш̆ Ш̑ Щ̆ Ꚗ Ꚗ̆ Ъ̄ Ъ̈ Ъ̈̄ Ꙑ Ы̂ Ы̃ Ѣ́ Ѣ̈ Ѣ̆ Ꙓ Э̨ Э̂ Ꙕ Ю̂ Ꙗ Я̈ Я̂ Я̨ Ԙ Ѥ Ѧ Ꙙ Ѫ Ꙛ Ѩ Ꙝ Ѭ Ѯ Ѱ Ѳ Ѵ Ѷ Ꙟ
List of Cyrillic letters List of Cyrillic multigraphs
v t e

Close

The letter most commonly represents the sound /ɔ/, like the o in "off". In Russian and Serbo-Croatian, it represents the sound /o/.

The Cyrillic letter О was derived from the Greek letter Omicron (Ο ο).

In Russian, O is used word-initially, after another vowel, and after non-palatalized consonants. Because of a vowel reduction processes, the Russian /o/ phoneme may have a number of pronunciations in unstressed syllables, including [ɐ] and [ə].

In Macedonian, Bulgarian, Ukrainian and Belarusian, the letter represents the sound /ɔ/.

In Tuvan the Cyrillic letter can be written as a double vowel.^[2][3]

• Ο ο : Greek letter Omicron
• O o : Latin letter O
• 0 : Digit Zero
• Ё ё : Cyrillic letter Yo
• Ѻ ѻ : Cyrillic letter Broad On
• Ӧ ӧ : Cyrillic letter O with diaeresis
• Ө ө : Cyrillic letter Oe
• Ӫ ӫ : Cyrillic letter Oe with diaeresis
• Ҩ ҩ : Cyrillic letter O-hook

Exotic glyph variants of Cyrillic O are available only in Unicode:^{[4][5][6][7][8]}

• broad Ѻ/ѻ:
  • CYRILLIC CAPITAL LETTER ROUND OMEGA: U+047A
  • CYRILLIC SMALL LETTER ROUND OMEGA: U+047B
• narrow ᲂ does not just represent itself, but also used in digraph Oy/oy:
  • CYRILLIC SMALL LETTER NARROW O: U+1C82
  • CYRILLIC CAPITAL LETTER UK: U+0478 (deprecated in favor of combination of Cyrillic letters О and у, U+041E U+0443)
  • CYRILLIC SMALL LETTER UK: U+0479 (deprecated in favor of combination of Cyrillic letters о and у, U+043E U+0443 or U+1C82 U+0443)
• with a cross inside (Ꚛ/ꚛ):
  • CYRILLIC CAPITAL LETTER CROSSED O: U+A69A
  • CYRILLIC SMALL LETTER CROSSED O: U+A69B
• doubled Ꚙ/ꚙ:
  • CYRILLIC CAPITAL LETTER DOUBLE O: U+A698
  • CYRILLIC SMALL LETTER DOUBLE O: U+A699
• eyed Ꙩ/ꙩ:
  • CYRILLIC CAPITAL LETTER MONOCULAR O: U+A668
  • CYRILLIC SMALL LETTER MONOCULAR O: U+A669
• two-eyed (Ꙫ/ꙫ, Ꙭ/ꙭ):
  • CYRILLIC CAPITAL LETTER BINOCULAR O: U+A66A
  • CYRILLIC SMALL LETTER BINOCULAR O: U+A66B
  • CYRILLIC CAPITAL LETTER DOUBLE MONOCULAR O: U+A66C
  • CYRILLIC SMALL LETTER DOUBLE MONOCULAR O: U+A66D
• many-eyed ꙮ:
  • CYRILLIC LETTER MULTIOCULAR O: U+A66E
• combining O for Church Slavonic abbreviations (as трⷪца = троица '(Holy) Trinity'):
  • COMBINING CYRILLIC LETTER O: 2DEA