Sandra Oh, a Korean-Canadian actress

O is a Chinese family name, represented by 柯 Ō is a Japanese family name. Ō (often romanized as "Oh" or "O" or even "Ou") is a rare family name which is the local interpretation of Wang in Chinese. Ō is the way Japanese pronounce the character 王 and is also the word for "king". Most Japanese with such a surname are Chinese descendants.

O or Oh is also a Korean name, spelled 吳 in hanja (i.e. Wu) and 오 in hangul. Ou is also a Chinese name. People who have this name include:

O Rissei, a famous Go player

Sadaharu Oh, the all-time home run king of Japan