| Type: | Bishop |
| Honorific-Prefix: | Most Reverend |
| Pietro Orsini | |
| Bishop of Aversa | |
| Church: | Catholic Church |
| Diocese: | Diocese of Aversa |
| Term: | 1591–1598 |
| Predecessor: | Giorgio Manzoli |
| Successor: | Bernardino Morra |
| Consecration: | 17 Apr 1580 |
| Consecrated By: | Giulio Antonio Santorio |
| Death Date: | 1598 |
| Death Place: | Aversa, Italy |
| Previous Post: | Bishop of Spoleto (1581–1591) |
Pietro Orsini (died 1598) was a Roman Catholic prelate who served as Bishop of Aversa (1591–1598) and Bishop of Spoleto (1581–1591).
On 11 Apr 1580, Pietro Orsini was appointed during the papacy of Pope Gregory XIII as Coadjutor Bishop of Spoleto and Titular Bishop of Hippos. On 17 Apr 1580, he was consecrated bishop by Giulio Antonio Santorio, Cardinal-Priest of San Bartolomeo all'Isola, with Paolo Odescalchi, Bishop Emeritus of Penne e Atri, and Ludovico Taverna, Bishop of Lodi, serving as co-consecrators. On 16 May 1581, he succeeded Flavio Orsini as Bishop of Spoleto. On 5 Apr 1591, he was appointed during the papacy of Pope Gregory XIII as Bishop of Aversa, he succeeded Giorgio Manzolo as Bishop of Aversa. He served as Bishop of Aversa until his death in 1598.