Санта-Пуденциана
In the consistory of 23 June 1777, Pope Pius VI made Gioannetti a cardinal "in pectore". This was published in the consistory of 15 December 1777, and Gioannetti received the red hat on 18 December 1777. He was awarded the pallium and the titular church of Santa Pudenziana on 30 March 1778.