The Crișul Negru (Black Criș) (Romanian), (Hungarian: Fekete-Körös) is a river in western Romania (Transylvania) and south-eastern Hungary (Békés County). The river has its source in the western Apuseni Mountains of Romania.
Flowing through the Romanian towns of Ștei and Beiuș and crossing the border of Hungary, the river, now called Fekete-Körös, joins the Fehér-Körös a few kilometres north from Gyula to form the Körös river. In Romania, its length is 164 km (102 mi) and its basin size is 3,820 km2 (1,470 sq mi).