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

all caps Nasal bilabial click Caron P&O O-methylated flavonoid O (disambiguation) O visa O-GlcNAc O A e o Z O Antiphons Douglas O-38 O class O line O lucenti, o sereni occhi Pui O O series Tai O Big O Ping-O-Tronic O Come, O Come, Emmanuel Big O notation O. Henry Award O-ring Haplogroup O-M119 Yeshe-Ö O Tannenbaum Ó Paí, Ó O Tempo e o Vento P&O Cruises O-type star Ó Rothláin