Small form of the katakana character オ (o).
- Small combining form of katakana オ (o) used to explicitly specify the vowel part of the previous katakana character, or to show a speaker's pronunciation or extension of that vowel.
- フォ - the sound [ɸo] rather than [ɸu] (フ) or [ho] (ホ)
- シフォン - transliteration of French chiffon
The katakana syllabary is used primarily for transcription of foreign language words into Japanese and the writing of gairaigo (loan words), as well as to represent onomatopoeias, technical and scientific terms, and the names of plants, animals, and minerals. It is also occasionally used in some words for emphasis, or to ease reading; katakana may be preferred for words becoming buried in the text if they are written under their canonical form in hiragana. Names of Japanese companies, as well as certain Japanese language words such as colloquial terms, are also sometimes written in katakana rather than the other systems. Formerly, female given names were often written in katakana. 
- ぉ (hiragana small o)
- オ (full-size o)
- (Katakana) 片仮名; アァ, イィ, ウゥヴ, エェ(𛀀), オォ, カヵガ, キギ, クㇰグ, ケヶゲ, コゴ, サザ, シㇱジ, スㇲズ, セゼ, ソゾ, タダ, チヂ, ツッヅ, テデ, トㇳド, ナ, ニ, ヌㇴ, ネ, ノ, ハㇵバパ, ヒㇶビピ, フㇷブプ, ヘㇸベペ, ホㇹボポ, マ, ミ, ムㇺ, メ, モ, ヤャ, , ユュ, エ/, ヨョ, ラㇻラ゚, リㇼリ゚, ルㇽル゚, レㇾレ゚, ロㇿロ゚, ワヮヷ, ヰ𛅤ヸ, , ヱ𛅥ヹ, ヲ𛅦ヺ, ン𛅧, ー, ヽ, ヾヿ
- (Southern Min additional) ウ̅ゥ̅, オ̅, カ̣,キ̣, ク̣, ケ̣, コ̣, サ̅サ̣̅, セ̅セ̣̅, ソ̅ソ̣̅, タ̣, チ̣, チ̅チ̣̅, ツ̣ツ̅ツ̣̅, テ̣, ト̣, パ̣, ピ̣, プ̣, ペ̣, ポ̣, , , , , , ,