O Unicode subscripts and superscripts Octonion Fraktur Enclosed Alphanumeric Supplement Ordinal indicator Enclosed Alphanumerics Ö Ɵ Oʻ Õ Ò Ó Open-mid back rounded vowel Ǫ ⱺ Ø Ơ O͘ Mid back rounded vowel Breve Ꝍ Circumflex Ǫ́ Inverted breve Open O O' Mid front rounded vowel Dot (diacritic) Bilabial click Macron (diacritic) Vietnamese alphabet Double grave accent International Phonetic Alphabet Livonian language Hook above Ogonek Mid central vowel Shift Out and Shift In characters R-colored vowel Uralic Phonetic Alphabet Nasal vowel Double acute accent Scribal abbreviation Ring (diacritic) Diethyl ether Cedilla Nasal bilabial click Small caps Caron P&O O visa O-methylated flavonoid …

O (disambiguation) O A e o Z O-GlcNAc O Antiphons Douglas O-38 O class O lucenti, o sereni occhi O line Pui O O series Tai O Big O Ping-O-Tronic Big O notation O Come, O Come, Emmanuel O Tempo e o Vento O. Henry Award Haplogroup O-M119 O-ring Yeshe-Ö O Tannenbaum Ó Paí, Ó O le Ao o le Malo O-type star