Cognomen Hiroyama (Hiroyama 
) , in all the world, is a very rare surname. The last name Hiroyama is characteristic of Brazil, where it is a very rare surname, the United States, where it is an extremely rare surname, and China. More frequently, Hiroyama is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Hiroyama | Japan, China, Philippines, United States, Brazil |