Cognomen ธิร (Thira 
, ธิร ) , around the world, is quite a rare last name. The family name ธิร is habitual in Romania, where it is a rare surname, Kenya, and Myanmar. In absolute terms, it most frequently occurs in Indonesia, Kenya, and Myanmar. Also, ธิร is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Thira | Indonesia, Myanmar, Kenya, India, Thailand |
| ธิร | Thailand |