O (kana)

o
hiragana katakana
transliteration	o
hiragana origin	於
katakana origin	於
spelling kana	大阪のオ (Ōsaka no "o")

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 at right (ordered by columns, from right to left), お lies in the first column (あ行, "column A") and the fifth row (お段, "row O"). Both represent [o].

Form	Rōmaji	Hiragana	Katakana
Normal a/i/u/e/o (あ行 a-gyō)	O	お	オ
	Ou Ō	おう, おぅ おお, おぉ おー, お～	オウ, オゥ オオ, オォ オー, オ～

Derivation

お and オ originate, via man'yōgana, from the kanji 於.

Variant forms

Scaled-down versions of the kana (ぉ, ォ) are used to express morae foreign to the Japanese language, such as フォ (fo).

Stroke order

Stroke order in writing お

Stroke order in writing オ

The hiragana お is made with three strokes:

1. A horizontal line from left to right.
2. A stroke consisting of a vertical line, a small diagonal line going upwards and to the left, and an open curve heading right and downwards.
3. A small curved stroke on the right.

The katakana オ is made with three strokes:

1. At the top, a horizontal stroke from left to right.
2. A downward vertical stroke cutting through the first stroke, with a small hook at the end facing left.
3. At the intersection of the first two strokes, a diagonal line going downwards and to the left.

Other communicative representations

• Computer encodings

Character	お		オ		ｵ
Unicode name	HIRAGANA LETTER O		KATAKANA LETTER O		HALFWIDTH KATAKANA LETTER O
Encodings	decimal	hex	decimal	hex	decimal	hex
Unicode	12362	U+304A	12458	U+30AA	65397	U+FF75
UTF-8	227 129 138	E3 81 8A	227 130 170	E3 82 AA	239 189 181	EF BD B5
Numeric character reference	お	お	オ	オ	ｵ	ｵ
Shift JIS	130 168	82 A8	131 73	83 49	181	B5

Character	ぉ		ォ		ｫ
Unicode name	HIRAGANA LETTER SMALL O		KATAKANA LETTER SMALL O		HALFWIDTH KATAKANA LETTER SMALL O
Encodings	decimal	hex	decimal	hex	decimal	hex
Unicode	12361	U+3049	12457	U+30A9	65387	U+FF6B
UTF-8	227 129 137	E3 81 89	227 130 169	E3 82 A9	239 189 171	EF BD AB
Numeric character reference	ぉ	ぉ	ォ	ォ	ｫ	ｫ
Shift JIS	130 167	82 A7	131 72	83 48	171	AB

• Braille

お / オ in Japanese Braille
お / オ o	おう / オー ō/ou

• Japanese semaphore

• Phonetic alphabet: 「大阪のオ」 ("o as in Osaka")
• Morse code: ・－・・・