[1][2][3][4][5][6][7][8] On 3 December 1640, Giovanni de Rossi was appointed during the papacy of Pope Urban VIII as Bishop of Cefalonia e Zante.
[1][2] On 9 December 1640, he was consecrated bishop by Giulio Cesare Sacchetti, Cardinal-Priest of Santa Susanna, with Leonardo Mocenigo, Archbishop of Candia, and Lelio Falconieri, Titular Archbishop of Thebae, serving as co-consecrators.
[2] On 10 July 1645, he was appointed during the papacy of Pope Innocent X as Bishop of Chiron.
[1][2] On 10 November 1653, he was appointed during the papacy of Pope Innocent X as Bishop of Ossero.
[1][2] He served as Bishop of Ossero until his death in 1667.