Leonello d'Este, Marquis of Ferrara, Italian noble (died 1450)

Leonello d'Este was Marquess of Ferrara, Modena, and Reggio Emilia from 1441 to 1450. Despite the presence of legitimate children, Leonello was favoured by his father as his successor. In addition, his virtuous qualities, high level of education, and popularity among the common people as well as his formal papal recognition ultimately made him the most suitable heir.