Surname Grassens (Grassens 
) , across the world, is a very rare cognomen. The family name Grassens is habitual in Netherlands, where it is a rare surname, Australia, where it is a very rare surname, and Canada, where it is an extremely rare surname. Measured by absolute frequency, it most frequently occurs in Netherlands, Australia, and the United States.
| VARIANT | COUNTRY |
|---|---|
| Grassens | Australia, United States, Netherlands, Canada |