| Type: | Bishop |
| Honorific-Prefix: | Most Reverend |
| Giovanni Battista Alfieri | |
| Bishop of Fano | |
| Church: | Catholic Church |
| Diocese: | Diocese of Fano |
| Term: | 1649–1676 |
| Predecessor: | Alessandro Castracani |
| Successor: | Angelo Maria Ranuzzi |
| Consecration: | 2 Jan 1650 |
| Consecrated By: | Marcantonio Franciotti |
| Birth Place: | Ostra Vetere, Italy |
| Death Date: | 17 Sep 1676 |
Giovanni Battista Alfieri (died 1676) was a Roman Catholic prelate who served as Bishop of Fano (1649–1676).
Giovanni Battista Alfieri was born in Ostra Vetere, Italy.On 9 Dec 1649, he was appointed during the papacy of Pope Innocent X as Bishop of Fano.On 2 Jan 1650, he was consecrated bishop by Marcantonio Franciotti, Cardinal-Priest of Santa Maria della Pace, with Giovanni Battista Rinuccini, Archbishop of Fermo, and Giambattista Spínola (seniore), Archbishop of Acerenza e Matera, serving as co-consecrators.He served as Bishop of Fano until his death on 17 Sep 1676.
While bishop, he was the principal co-consecrator of Baldassarre Bonifazio, Bishop of Capodistria (1653); and Francesco de Andreis, Bishop of Nona (1653).