Cognomen เถา (Thao 
, เถา 
) , across the world, is a common last name. The surname เถา is characteristic of Macao, where it is quite a common surname, Vietnam, and Laos. Not in comparison with a country's population, this name is the most popular in Vietnam, the United States, and Malaysia. Also, เถา is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Thao | Japan, Vietnam, United States, Malaysia, Laos |
| เถา | Thailand |