Altdöbern (Lower Sorbian Stara Darbnja) is a municipality in the Oberspreewald-Lausitz district, in southern Brandenburg, Germany.

The flat landscape is dominated by large forests and new lakes created from the remainings of former opencast lignite mines since the 1990s.

The first castle was built in the 16th century in renaissance style, but later replaced by a new building in baroque architecture including rococo elements.

Intense restorations are still in progress, but the interior of the castle can be visited during special events such as the annual park festival (Parksommerträume).

Railway stop Haltepunkt Altdöbern gives regional connections to Berlin, Cottbus and Dresden (via Senftenberg).