Kreis Meseritz (Landkreis Meseritz as of 1939; Polish: Powiat międzyrzecki) was a district in Prussia, first in the southern administrative Region of Posen within the Prussian Province of Posen (till 1920), then within the Province of the Frontier March of Posen-West Prussia (till 1 October 1938) and at last as part of the administrative Region of Frankfurt within the Province of Brandenburg (till 1945).