Surname Каслов (Kaslov 
, Каслов 
) , across the world, is a rare cognomen. The cognomen Каслов is characteristic of Denmark, where it is a rare surname, Israel, where it is a very rare surname, and the United States. Measured by absolute frequency, it is the most numerous in the United States, Russia, and Denmark.
| VARIANT | COUNTRY |
|---|---|
| Kaslov | Russia, United States, Canada, Denmark, Israel |
| Каслов | Kazakhstan, Russia, Ukraine |