Last name คำรุณ (Khamrun 
, Kumrun 
, คำรุณ) , worldwide, is a rare cognomen. The family name คำรุณ is habitual in Thailand, where it is a very rare surname, India, where it is an extremely rare surname, and Canada. More prevalently, คำรุณ is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Khamrun | India, United States, Thailand |
| Kumrun | Canada, India, Bangladesh, Malaysia, United States |