Surname อุ่นชัย (Unchai 
, Ounchai , อุ่นชัย) , in the entire world, is a rare cognomen. The cognomen อุ่นชัย is characteristic of Thailand, where it is a rare surname, Malaysia, where it is an extremely rare surname, and the United States. In absolute terms, it is commonest in Thailand, the United States, and India. Very seldom, อุ่นชัย is the forename as well as the last name.