Surname ธนญ (Thanon 
, ธนญ , Thanjan 
) , all around the world, is a rare cognomen. The last name ธนญ is habitual in Iraq, where it is a rare surname, Thailand, and Malaysia. Likewise, ธนญ is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Thanon | Australia, Thailand, India, Iraq, United States |
| ธนญ | Thailand |
| Thanjan | Malaysia, Thailand, India, United States, South Africa |