Surname Tianchai (เทียนชัย 
, Tianchai 
, เทียรชัย ) , in all the world, is quite a rare cognomen. The cognomen Tianchai is habitual in Thailand, where it is quite a rare surname, Malaysia, where it is a very rare surname, and China, where it is an extremely rare surname. More frequently, Tianchai is the forename as well as the last name.