Ostrava, city, northeastern Czech Republic. It lies between the Ostravice and Oder rivers above their confluence at the southern edge of the Upper Silesian coalfield. It was founded about 1267 as a fortified town by Bruno, bishop of Olomouc, to protect the entry to Moravia from the north. Its castle was demolished in 1495. Historic buildings include the 13th-century Church of St. Wenceslas and the Old Town Hall tower (1687). There are several theaters, including a fine opera house, a philharmonic orchestra, and an art gallery.
Ostrava is surrounded by a rich black-coal basin that has made it a center of heavy industry, with a long tradition dating from 1830, when the first blast furnace was built at the Vítkovice ironworks. Some of the coal pits extend into the city limits, and their derricks are common features of the skyline.
The conurbation of Greater Ostrava receives a steady influx of workers, and many housing estates and new towns, such as Poruba and Havířov, have been built there. Most planned development is east of the Ostravice River, in Slezská (“Silesian”) Ostrava. Settlements west of the Ostravice are in Moravská (“Moravian”) Ostrava.
The population of the region is employed predominantly in mining (at Ostrava, Karviná, and Orlová) and in metalworking (at Vítkovice, Kunčice, and Třinec). Manufactures also include mining machinery at Opava, railway cars at Studénka, and automobiles at Kopřivnice. The coal mining also supports chemical (ammonia and nitrate fertilizers) and power industries. The Technical University of Mining and Metallurgy of Ostrava (1716) is located there. Pop. (2021) 282,450.