Cognomen Ostrek (Ostrek 
) , in the world, is a very rare family name. The last name Ostrek is habitual in Slovenia, where it is a rare surname, Poland, where it is a very rare surname, and Croatia. In absolute terms, it is the most numerous in Japan, Poland, and Slovenia. Much less frequently, Ostrek is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Ostrek | Japan, Slovenia, United States, Poland, Croatia |