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

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