Sebastiano Perissi was born in
Boccheggiano,
Italy in 1631, but raised in
Siena. Perissi obtained the degree of
Doctor in utroque iure in Siena. He was Auditor in the nunciature in Florence, and then Vicar General of Naples. On 9 January 1692, he was appointed during the papacy of
Pope Innocent XII as
Bishop of Nocera de' Pagani. On 20 January 1692, he was
consecrated bishop by
Bandino Panciatici,
Cardinal-Priest of
San Pancrazio, with
Giuseppe de Lazzara,
Bishop of Alife, and
Giuseppe Felice Barlacci,
Bishop Emeritus of Narni, serving as
co-consecrators. On 28 May 1700, he was appointed during the papacy of Pope Innocent XII as
Bishop of Grosseto. He served as Bishop of Grosseto until his death in November 1701. ==Episcopal succession==