Cognomen Siwetu (Siwetu 
) , across the world, is an extremely rare surname. The family name Siwetu is characteristic of Sub-Saharan Africa, particularly South Africa, where it is an extremely rare surname. Much more prevalently, Siwetu is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Siwetu | South Africa, Tanzania |