Cognomen Willathgamuwa (Willathgamuwa 
) , in the world, is a rare last name. The family name Willathgamuwa is habitual in Sri Lanka, where it is a rare surname, Australia, where it is a very rare surname, and the United States, where it is an extremely rare surname.
| VARIANT | COUNTRY |
|---|---|
| Willathgamuwa | United States, Australia, Sri Lanka |