Cognomen Oyandza-Koumou (Oyandza-Koumou 
) , around the world, is a rare last name. The last name Oyandza-Koumou is habitual in Sub-Saharan Africa, particularly the Democratic Republic of the Congo, where it is a rare surname. Parts of the name also exists independently as a last name Oyandza, and a last name Koumou.
| VARIANT | COUNTRY |
|---|---|
| Oyandza-Koumou | Democratic Republic of the Congo |