Tenuta San Guido is a famous Italian winery located on the Tyrrhenian coast, in the Maremma region, between Livorno and Grosseto. It owes its name to Saint Guido della Gherardesca who lived in the 11th century.

The marriage of Mario Incisa della Rocchetta and Clarice della Gherardesca in 1930 marked the beginnings of the estate, with the planting of Cabernet Sauvignon vines that would give a few years later the great red wine of Sassicaia, based on the ideal model of the time: Bordeaux. Mario Incisa made the decision to plant this grape variety because of the similarity of the stony and gravelly soils of Tuscany with those of the Graves in Bordeaux. However, the success was not immediate and it was not until the end of the sixties that it was understood that the ageing of these wines in the cellar gave them a unique complexity. The first vintage was marketed in 1968.

This was a fundamental change in the tradition of Tuscan and Piedmontese wines, whose emblematic grape varieties until then had been Sangiovese and Nebbiolo,

The winery has given its name to an appellation, "Bolgheri Sassicaia" and it is the only one of its kind in Italy.