Cognomen ثو (Thu 
, Tho 
, Thou 
) , worldwide, is a prevalent surname. The surname ثو is characteristic of Myanmar, where it is a prevalent surname, Macao, where it is a common surname, and Vietnam, where it is quite a common surname (explore the name in all countries). Not in comparison with a country's population, it is commonest in South-eastern Asia, particularly Myanmar, Vietnam, and Malaysia. Very seldom, ثو is the forename as well as the last name.