The Giudicato of Arborea (Italian: Giudicato di Arborea, Sardinian: Giuigadu de Arborea) is one of the four independent, hereditary "judicatures" (giudicati) into which the island of Sardinia is divided in the High Middle Ages.

It occupies the central-west portion of the island, wedged between Logudoro to the north and east, Cagliari to the south and east, and the Mediterranean Sea to the west.

To the north west and beyond Logudoro is located Gallura, with which Arborea has far less interaction.

Arborea outlasts her neighbors, surviving well into the 15th century.

The earliest known judicial seat is Tharros (Tarra).

Giudicato of Arborea at the times of its maximum expansion occupies the whole island's territory, except the cities of Alghero and Cagliari.