Áo is the Mandarin pinyin and Wade–Giles romanization of the Chinese surname written 敖 in Chinese character. It is romanized as Ngo in Cantonese. Ao is listed 375th in the Song dynasty classic text Hundred Family Surnames. As of 2008, it is the 261st most common surname in China, shared by 250,000 people.In Japanese, Ao is Japanese surname written 粟生 in Chinese character. Source: Wikipedia (en)