Eleanor of Arborea (Sardinian: Elianora de Bas; Catalan: Elionor d'Arborea or Elionor de Molins de Rei; Molins de Rei, Catalonia, 1347 – Oristano/Aristanis, Sardinia, 1404) was the giudicessa ("female judge") of Arborea from 1383 to her death. She was one of the last, most powerful and significant Sardinian judges, as well as the island's most renowned heroine.

Born at Molins de Rei, Catalonia, Eleanor of Bas-Serra was the daughter of Marianus IV of Arborea, who had become in 1346 giudice of Arborea, on the west coast of Sardinia, and his wife Timbora de Rocabertí. It has been said that their family, the Bas, belonged to the House of Visconti^{[citation needed]}. The house of Arborea, whose power extended over about one third of Sardinia, was the only independent part of the island at that point in history. During her childhood, she was raised with a natural tendency towards war and weapons.

Her father married Eleanor to Brancaleone Doria, a Genoese nobleman who held the fief of Castelgenovese, in order to strengthen local alliances. Marianus died in 1376 and was succeeded by his son Hugh III. In March 1383, there was a republican uprising in Arborea and Hugh was murdered. Eleanor defeated the rebels and became regent to her infant son Frederick, who as next male heir became the official monarch of Arborea.

Arborea is a town and comune in the province of Oristano, Sardinia, Italy, whose economy is largely based on agriculture, with production of vegetables and fruit.

Arborea was built by the fascist government of Italy in the 1920s, after the draining of the marshes which covered the area. The village was populated by families (mostly composed of peasants) who came from the regions of Veneto and Friuli (North-eastern Italy).

Arborea is named for and lies within the medieval Giudicato of Arborea, which had its capital, at various periods, in nearby Tharros and Oristano. The town was originally named Villaggio Mussolini (with which it was inaugurated on October 29, 1928), by the fascist government. Less than two years later, the name was revised to Mussolinia di Sardegna ("Mussolinia of Sardinia", to distinguish the town from Mussolinia di Sicilia, now Santo Pietro in the commune of Caltagirone, Catania). The current name was adopted after World War II.