Potsdam-Mittelmark is a Kreis (district) in the western part of Brandenburg, Germany. Area 2682 km², population 205,800 (2002). The district's capital is Belzig[?].
The cities of Potsdam and Brandenburg are surrounded by, but not part of the district. The district includes the southern banks of the Havel river and the northern parts of the Fläming (a wooded hill chain).
Towns in the district: Belzig[?], Beelitz[?], Teltow[?], Werder[?].