Sosnowiec, city in southern Poland, in Katowice Province, on a tributary of the Wisla (Vistula) River. Sosnowiec is a rail junction and an industrial center in the important coal-mining region of Upper Silesia. Manufactures include iron and steel, textiles, glass, and machinery. A 17th-century castle is in the city. Sosnowiec passed to Prussia in 1795 and to Russia in 1815. Its industrial expansion began in the late 19th century with the exploitation of nearby coalfields. In 1919 the city again became part of Poland. Population (1997 estimate) 244,000.
