Cognomen Janasiak (Janasiak 
) , all around the world, is a rare surname. The cognomen Janasiak is habitual in Poland, where it is a rare surname, the United States, where it is a very rare surname, and France. Likewise, Janasiak is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Janasiak | Germany, Poland, France, United States |
| agnieszka janasiak Polish sportsperson and athletics competitor, PL (b. 1981) |
|