[1] He was born to Giovanni, IV count of Mazarin, and Dorotea Barresi Santapau, princess of Pietraperzia.
In April 1566, upon the death of his father, he was awarded his fiefdoms under regency; for which he was reinvested formally on 16 November 1557.
In 1580, his maternal great-uncle Francesco Santapau Branciforte, prince of Butera, who had no children, designated Fabrizio as heir of the Principality of Butera and of the fief of Occhiolà, of which he was invested on the 8th December 1591, as well as of the Principality of Pietraperzia, inherited from his mother who died in that same year.
The administration of the family assets passed to the eldest son Francesco Branciforte Barresi, with whom he had numerous quarrels and who had him banned from Palermo until 1621.
Fabrizio Branciforte Barresi and his wife, the marchesa Caterina Barresi Branciforte, had nine children: Francesco, Giovanni, Vincenzo, Pietro, Filippo, Dorotea, Caterina, Imara, and Isabella.