Yau is a surname. It is a romanisation of multiple surnames in Cantonese speaking regions (including Hong Kong) based on different varieties of Chinese, as well as a surname in other cultures.
Among respondents to the 2000 United States Census, Yau was the 394th-most common surname among Asian Pacific Americans, and 10,881th-most common overall, with 2,686 bearers (93.9% of whom identified as Asian/Pacific Islander).[1]