city, capital of Bihor judeţ (county), northwestern Romania. It lies about 8 miles (13 km) east of the Hungarian border, along the Crişul Repede River where it leaves the western foothills of the Western Carpathians and flows onto the Hungarian Plain.

One of the first feudal states in the area, a principality ruled by Prince Menumorut at the end of the 9th and beginning of the 10th centuries, was centred on a citadel at Biharea, northwest of Oradea. The citadel of Oradea was erected between 1114 and 1131, destroyed by the Tatars in 1241, and rebuilt in the 15th century under the Corvinus dynasty. Between 1660 and 1692 the community was occupied by the Turks; it then became Hungarian until it joined Romania in 1918.

Oradea is a cultural centre, with a state theatre, puppet theatre, philharmonic orchestra, regional library, and museum. Five miles east of Oradea are the spas of Băile 1 Mai and Băile Felix. Since World War II, Oradea has become a major industrial centre, producing machine tools, mining equipment, chemicals, processed foods, and footwear. Pop. (2007 est.) 205,077.