Río Negro (Spanish pronunciation: [ˈri.o ˈneɣɾo], Black River) is a province of Argentina, located in northern Patagonia. Neighboring provinces are from the south clockwise Chubut, Neuquén, Mendoza, La Pampa and Buenos Aires. To the east lies the Atlantic Ocean.

Its capital is Viedma near the Atlantic outlet of the province’s namesake river in the eastern extreme. The largest city is in the Andean foothills Bariloche in the far west. Other important cities include General Roca and Cipolletti.