Cognomen Янкоуски (Янкоуски 
, Jankouski 
, Yankouski 
) , across the world, is a very rare family name. The last name Янкоуски is habitual in Lithuania, where it is a rare surname, Belarus, and Belgium, where it is a very rare surname. Not in comparison with a country's population, it is the most numerous in Russia, Belarus, and the United States.
| VARIANT | COUNTRY |
|---|---|
| Янкоуски | Russia |
| Jankouski | Brazil, United States, Belgium |
| Yankouski | United States, Lithuania, Belarus |