O
| Senator | Years | Province | Party |
|---|---|---|---|
| Pacho O'Donnell | 1998 - 1998 | Buenos Aires City | Justicialist Party |
| Nicasio Oroño | 1868 - 1877 | Santa Fe |
Read more about this topic: List Of Former Argentine Senators
O
| Senator | Years | Province | Party |
|---|---|---|---|
| Pacho O'Donnell | 1998 - 1998 | Buenos Aires City | Justicialist Party |
| Nicasio Oroño | 1868 - 1877 | Santa Fe |
Read more about this topic: List Of Former Argentine Senators