Sosnowiec, city, Śląskie województwo (province), southern Poland. It lies along the Czarna Przemsza River, which is a tributary of the Vistula River. A rail junction in the Silesian Upland, Sosnowiec has numerous heavy-industrial plants and coal mines. It is also the home of Poland’s first mining museum.
A castle was built in Sosnowiec in the 17th century. The city was rebuilt after a disastrous fire in 1830 and began to prosper with the building of the Warsaw-Vienna rail line in 1845. It had become an industrial centre by the end of the 19th century. Town rights were acquired in 1902. By the time of its centennial in 2002, it had augmented its industrial activities with commercial and service-oriented businesses. Pop. (2011) 216,420.