​SOMMERFELD, a town of Germany, in the Prussian province of Brandenburg, on the Lubis, 40 m. S.E. of Frankfort-on-Oder, by the railway from Berlin to Breslau. Pop. (1905), 12,251. It has a Roman Catholic church, three Evangelical churches, several schools and a hospital. Its manufactures of woollen cloth are important; and it also contains finishing and dyeworks, an ironfoundry, boiler-works and breweries.