Su is the pinyin romanization of the common Chinese surname written 苏 in simplified characters and 蘇 traditionally.

蘇 and 苏 are also romanized So and Sou in Cantonese; Soh and Souw in Southern Min dialects; and Thu in Gan.

[6][7] One origin derives from Fan, purported to be the eldest grandson of the six great-great-great-great-grandsons of the Yellow Emperor and said to have lived in Kunwu (昆吾), the northeast region of Yuncheng in Shanxi.

This perished in the late Shang dynasty – whose fall was traditionally blamed upon the beautiful concubine Su Daji, – but its rulers and people took the state's name as their clan name and moved elsewhere.

Prior to the Qin dynasty, the Su clan mainly resided in Henan and Hebei, but, during the Warring States period, one group moved southward into Hubei and Hunan and another west into Shaanxi.

Another origin was from a Han-era ethnic group in Liaodong, whose family name Wuyuanyousu (烏垣有蘇) was later shortened into Su during the Northern Wei.

Participants hail from China, Taiwan, Singapore, Malaysia, Indonesia, Thailand, South Korea, the Philippines, Australia, America and Europe.