Cognomen ศิริจันทร์ (ศิริจันทร์ 
, Sirijan 
, Sirichan 
) , in the entire world, is quite a rare family name. The last name ศิริจันทร์ is characteristic of Thailand, where it is quite a rare surname, and India, where it is an extremely rare surname. Likewise, ศิริจันทร์ is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| ศิริจันทร์ | Thailand |
| Sirijan | United States, South Africa, India, Thailand |
| Sirichan | Malaysia, Thailand, India, United States, New Zealand |
| Sirijun | United States, India, Thailand |
Sirachant, Sirichand, Sirichant, and Sirichantr