Last name Rønnau (Rønnau 
) , around the world, is a very rare family name. The family name Rønnau is habitual in Northern Europe, particularly Denmark, where it is a rare surname.
| VARIANT | COUNTRY |
|---|---|
| Rønnau | Denmark |
|
cornelius thomas rønnau NO (b. 1752) |
|
|
jørn robert rønnau DK (b. 1944) |
|