The Magro or Magre is a river in the eastern Iberian Peninsula. It is a left-bank tributary of the Júcar.
The source is located at 1,100 metres above sea level in the Sierra de Mira, within the municipal limits of Aliaguilla, in the Spanish province of Cuenca. Immediately crossing the border between Castilla–La Mancha and the Valencian Community, it runs 130 km down to Algemesí, where it joins the Júcar. It generally features a modest flow. Together with the Escalona, Sallent, and Albaida, it contributes to most of the floods of the Júcar.
