Last name Ostroman (Ostroman 
) , in the world, is a rare surname. The cognomen Ostroman is characteristic of Croatia, where it is a rare surname, Canada, where it is a very rare surname, and Italy. Not in comparison with a country's population, it is the most numerous in Croatia, Italy, and the United States.
| VARIANT | COUNTRY |
|---|---|
| Ostroman | Croatia, Italy, Canada, United States, Argentina |