Mittelweser (Samtgemeinde)
Mittelweser is a Samtgemeinde ("collective municipality") in the district of Nienburg, in Lower Saxony, Germany. Its seat is in the village Stolzenau. It was formed on 1 November 2011 when the municipality Stolzenau joined the former Samtgemeinde Landesbergen.
As of 2025, the collective municipality has approximately 16,000 residents.
The Samtgemeinde Mittelweser consists of the following municipalities: