Villanueva de Viver is a municipality in Spain, located in the comarca of Alto Mijares within the province of Castellón, part of the Valencian Community. It lies in the mountainous inland north of the region, in an area characterised by rugged terrain and small, scattered settlements.
As a municipality, it forms the basic tier of local administration in Spain, with its own local government. Alto Mijares is one of the comarcas of the province of Castellón, a largely rural area of the Valencian interior.