Cognomen Irwantoro (Irwantoro 
) , in the world, is a rare last name. The last name Irwantoro is characteristic of South-eastern Asia, particularly Indonesia, where it is a rare surname, Singapore, where it is a very rare surname, and Malaysia. Very seldom, Irwantoro is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Irwantoro | Singapore, Malaysia, Indonesia |