OPPELN (Polish, Oppolie), the chief town of a district of its own name and the seat of government for Upper Silesia, Prussia, lies on the right bank of the Oder, 50 miles to the south-east of Breslau. It contains the oldest Christian church in the district, founded at the close of the 10th century, and a ducal palace of the 15th century, on an island in the Oder. The most prominent among the other buildings are the offices of the district authorities, the town-house, the normal seminary, and the hospital. The Roman Catholic gymnasium is established in an old Jesuit college. The industries of Oppeln include the manufacture of Portland cement, soap, cigars, and lime; and a trade is carried on by rail and river in cattle, grain, and the mineral produce of the district. The population in 1880 was 14,447, of whom 10,772 were Roman Catholics. The upper classes speak German, the lower Polish.

Oppeln was already a flourishing place at the beginning of the 11th century, and after 1132 was the capital of an independent duchy, which became a fief of Bohemia in 1327, and was absorbed by the empire in 1556.