Family name วัฒนเดช (วัฒนเดช 
, Wattanadet 
, Watthanadech ) , across the world, is a rare surname. The last name วัฒนเดช is characteristic of Thailand, where it is a rare surname, and the United States, where it is an extremely rare surname. Also, วัฒนเดช is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| วัฒนเดช, Watthanadech, Wattanadej | Thailand |
| Wattanadet | Thailand, United States |