Surname Käosaar (Käosaar 
) , worldwide, is an extremely rare last name. The family name Käosaar is habitual in Northern Europe, particularly Estonia, where it is a rare surname.
| VARIANT | COUNTRY |
|---|---|
| Käosaar | Estonia |
| juhan käosaar (b. 1909) |
|
|
|
irene käosaar estonian educationalist, EE (b. 1970) |
|