O (disambiguation) Ö Ơ Õ Ø Ó P&O O O' O-methylated flavonoid O visa Ò O Antiphons O A e o Z O-GlcNAc Douglas O-38 Open O O class O line Pui O O lucenti, o sereni occhi O series Tai O Big O O Tempo e o Vento Ping-O-Tronic O Come, O Come, Emmanuel Big O notation Oʻ O. Henry Award Haplogroup O-M119 Yeshe-Ö O-ring O Tannenbaum Ó Paí, Ó Ɵ O le Ao o le Malo