In the world, Siderius (Siderius 
) is an extremely rare boy's given name. Much more frequently, Siderius is the last name as well as the forename.
| VARIANT | COUNTRY |
|---|---|
| Siderius | Belgium, United States, India, Canada, Netherlands |
|
meinardus siderius French politician, FR (b. 1754) |
|
| poppe siderius Dutch civil servant, NL (b. 1922) |
|