Surname Tongja (Tongja 
) , across the world, is a very rare cognomen. The last name Tongja is characteristic of South-eastern Asia, particularly Thailand, where it is a very rare surname, and Philippines, where it is an extremely rare surname. Likewise, Tongja is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Tongja | India, Thailand, Nigeria, Philippines |