She was the second child of King John II of Castile and his first wife, Maria of Aragon.

Her father had her recognised as successor to the kingdom and as Princess of Asturias by the Cortes of Valladolid shortly after her sister's funeral.

The new Princess of Asturias received homage in the presence of her father, the King, in City of Burgos.

On 5 January 1425, she was displaced by the birth of a brother, the future King Henry IV of Castile.

Now merely infanta and second-in-line to the throne again, Eleanor died the same year near the Cistercian monastery in La Espina.