Worldwide, Westerdahl (Westerdahl 
) is a very rare boy's first name. The forename Westerdahl is habitual in Belgium, where it is a rare male name, and China, where it is an extremely rare masculine name. Much more frequently, Westerdahl is the last name as well as the forename.
| VARIANT | COUNTRY |
|---|---|
| Westerdahl | Switzerland, Sweden, United States, Denmark, Finland |