The Gherardeschi or della Gherardesca were a family of the Republic of Pisa, dating back as early as the 11th century. They were one of the most prominent in Pisa by the middle of the 13th century. They were of Ghibelline sympathies and held the county of Donoratico.
Constantine I of Gallura may have been a member of the family, ruling Gallura on behalf of the Archdiocese of Pisa.
The Gherardeschi had a rivalry with the House of Visconti, another Ghibelline family of Pisa. In 1237, the Archbishop and the Emperor Frederick II intervened in Pisa to reconcile the two rivals, but failed. In 1254, the citizenry rebelled and imposed twelve Anziani del Popolo ("Elders of the People") as their political representatives.
Early on in the century, the Gherardeschi took an interest in the affairs of Pisa in Sardinia. In 1230, Ubaldo of Gallura, a Visconti, invaded the Giudicato of Cagliari, but the Gherardeschi repulsed him in the name of Benedetta and the young William II. In 1258, they received a third of Cagliari after its dismemberment. Their third was the southern third, including the city of Cagliari itself. A Gherardesca woman also married John Visconti, the Judge of Gallura, who had received the northeastern third of Cagliari. This marriage brought final reconciliation between the Visconti and Gherardeschi.
The Gherardeschi reached their height in Pisa in the person of Ugolino della Gherardesca in the 1270s and 1280s. He was forced to share power with his nephew Nino Visconti, but they soon quarrelled. The fed-up Pisans arrested Ugolino and deposed Nino from Gallura.
There is a Gherardesca Chapel in the church of Saint Francis in Pisa.