| Image Coa: | Wappen Siedenburg.png |
| Coordinates: | 52.7°N 64°W |
| Image Plan: | Siedenburg in DH.svg |
| State: | Niedersachsen |
| District: | Diepholz |
| Samtgemeinde: | Siedenburg |
| Elevation: | 39 |
| Area: | 14.22 |
| Postal Code: | 27254 |
| Area Code: | 04272 |
| Licence: | DH |
| Gemeindeschlüssel: | 03 2 51 034 |
| Website: | www.siedenburg-online.de |
| Mayor: | Arnold Runge |
Siedenburg is a municipality in the district of Diepholz, in Lower Saxony, Germany. It is situated approximately 20 km west of Nienburg.
Siedenburg is also the seat of the Samtgemeinde ("collective municipality") Siedenburg.