Cognomen Sittiya (สิทธิยา 
, สิทธิญา , Sittiya 
) , all over the world, is a rare last name. The family name Sittiya is habitual in South-eastern Asia, particularly Thailand, where it is a rare surname. Also, Sittiya is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| สิทธิยา, สิทธิญา, สิทธิยะ | Thailand |
| Sittiya | Philippines, United States, India, Thailand |