Cognomen Олденбург (Oldenburg 
, Олденбург 
, Oldenbourg 
) , in the entire world, is a common surname. The surname Олденбург is habitual in Germany, where it is quite a rare surname, Denmark, and Netherlands. In absolute terms, it most frequently occurs in Germany, the United States, and Netherlands.
| VARIANT | COUNTRY |
|---|---|
| Oldenburg | Germany, Sweden, United States, Brazil, Netherlands |
| Олденбург | Russia, Ukraine |
| Oldenbourg | Germany, Mexico, United States, Canada, Brazil |