Last name ถง (Thong 
, ถง 
, Tongging 
) , across the world, is a common cognomen. The surname ถง is characteristic of South-eastern Asia, particularly Malaysia, where it is quite a common surname, Singapore, and Laos. Not in comparison with a country's population, it is the most numerous in South-eastern Asia, particularly Malaysia, Vietnam, and Indonesia. Likewise, ถง is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Thong | Laos, Singapore, Vietnam, Malaysia, Indonesia |
| ถง | Thailand |
| Tongging | Philippines, India |