The Júcar (Spanish: [ˈxukaɾ] ) or Xúquer (Valencian: [ˈʃukeɾ]) is a river in Spain, on the Iberian Peninsula. The river runs for approximately 509 km.

Its source is located at Ojuelos de Valdeminguete, in the municipality of Tragacete, province of Cuenca, on the eastern flank of the Montes Universales in the Sistema Ibérico. Its tributaries include the Cabriel, the Magro, and the Albaida [es].

The Júcar River flows first southward and then eastward through the towns of Cuenca, Alcalá del Júcar, Cofrentes, Alzira, Sueca, Alarcón and Cullera, a town located near its mouth into the Gulf of Valencia in the Mediterranean Sea. It crosses the provinces of Cuenca, Albacete and Valencia.

In 1982, the river Júcar broke the Tous Dam, causing the biggest flood in Spanish history, with a flow speed of 16,000 cubic metres per second, killing more than 30 people. This flood was the most important one in the whole history of Spain because, at that time, the people had thought that the Tous Dam was indestructible. The flood was called La pantanada de Tous.

• List of rivers of Spain
• Rambla del Poyo

• Confederació Hidrogràfica del Xúquer
• Plataforma Xúquer Viu
• Projecte de seguiment de la qualitat del Xúquer

39°10′22.28″N 0°17′41.07″W / 39.1728556°N 0.2947417°W / 39.1728556; -0.2947417