Cieszyn Silesia (Polish Śląsk cieszyński, Czech Těšínské Slezsko) is a historical region in south-eastern Silesia, between the Vistula and Oder rivers. It covers the area between the north-western part of the Carpathians, Oświęcim Valley, part of the Silesian Valley and eastern Sudetes.
The historical boundaries of the region are identical to those of the independent Duchy of Cieszyn. Currently the Cieszyn Silesia is one of the euroregions.