Beatrice Borromeo was born in Innichen on 18 August 1985. She is the daughter of Count Carlo Ferdinando Borromeo (born in 1935) and Paola Marzotto, and the maternal granddaughter of Marta Marzotto, ex-wife of Count Umberto Marzotto. Borromeo has stated that her parents never married. Her father has three daughters from a former marriage, Borromeo’s half-sisters: Isabella, Lavinia (married to Fiat executive John Elkann) and Mathilde. Borromeo also has a full brother, young Carlo, three years her senior. She is a descendant of the 16th century Roman Catholic cardinal, Saint Carlo Borromeo.