Tsai is a Chinese surname that derives from the name of the ancient Cai state. In 2019 it was the 38th most common surname in China, but the 9th most common in Taiwan, where it is usually romanized as Tsai, Tsay, or Chai based on Wade-Giles romanization of Standard Mandarin and the 8th most common in Singapore, where it is usually romanized as Chua, which is based on its Teochew and Hokkien pronunciation. Koreans use Chinese-derived family names and in Korean, Cai is 채 in Hangul, Chae in Revised Romanization, It is also a common name in Hong Kong where it is romanized as Choy, Choi or Tsoi. In Macao and Malaysia, it is spelled as Choi, in Malaysia and the Philippines as Chua or Chuah, in Thailand as Chuo (ฉั่ว). Moreover, it is also romanized in Cambodia as either Chhay or Chhor among people of full Chinese descent living in Cambodia and as Tjoa or Chua in Indonesia.
