Xiao (; Chinese: 蕭) is a Chinese-language surname. In the Wade-Giles system of romanization, it is rendered as Hsiao, which is commonly used in Taiwan. It is also romanized as Siauw, Shiao, Siaw, Siew, Siow, Seow, Siu, Shiu or Sui, as well as "Shaw" in less common situations, inspired by the transliteration of the surname of notable figures such as Irish playwright George Bernard Shaw and English actor Robert Shaw. It is the 99th name on the Hundred Family Surnames poem.

After the demise of the Qing dynasty, some of the descendants of Manchu clan Šumuru sinicized their clan name to the Chinese surnames Shu (舒), Xu (徐) or Xiao (蕭).

A 1977 study found that it was the 20th most common Chinese surname in the world. It is said to be the 30th most common in China. In 2019 it was the 33rd most common surname in Mainland China.