Family name Koellin (Koellin 
) , in the world, is an extremely rare last name. The surname Koellin is habitual in Netherlands, where it is a very rare surname, and the United States, where it is an extremely rare surname. Also, Koellin is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Koellin | India, United States, Netherlands |
| conrad koellin German theologian, DE (b. 1476) |
|