Surname Olaj (Olaj 
) , all around the world, is a rare cognomen. The surname Olaj is characteristic of Hungary, where it is quite a rare surname, Slovenia, and Croatia, where it is a rare surname. Very seldom, Olaj is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Olaj | Norway, Hungary, United Kingdom, Slovenia, Croatia |
| jože olaj SI (b. 1939) |
|
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| anton olaj Slovene police officer, SI (b. 1962) |
|