Khui o (toā-siá: Ɔ, sió-siá: ɔ, open o) sī Latin jī-bó (Latin alphabet) khok-chhiong--chhut-lâi ê 1 ê jī-bó. Kok-chè Im-phiau the̍h lâi piáu-sī khui-tiong aū îⁿ bó-im (open-mid back rounded vowel), iā tō sī Hō-ló-oē lāi-té (o ke 1 ê hô͘-lô͘-tiám) ê hoat-im. Chin chē Hui-chiu gí-giân ê bûn-jī ū ēng--tio̍h.

Thōng-iōng-bé siu-kái

Thong-iōng-bé kā toā-siá ê Ɔ pian tī Latin Khok-chhiong-B (Latin Extended-B block) ê U+0186, kā sió-siá ê ɔ pian tī U+0254.