Ráj is a district of the city of Karviná in Karviná District, Moravian-Silesian Region, Czech Republic. It was a separate municipality but in 1948 became administratively a part of the city of Karviná. It lies in the historical region of Cieszyn Silesia and has a population of 17,142 (2001).

Karviná is a city in the Moravian-Silesian Region of the Czech Republic. It has about 50,000 inhabitants. It lies on the Olza River in the historical region of Cieszyn Silesia.