| Pier Luigi Farnese | |
|---|---|
 | |
| Duke of Parma and Piacenza | |
| Reign | 16 September 1545 – 10 September 1547 |
| Successor | Ottavio |
| Born | 19 November 1503 Rome, Papal States |
| Died | 10 September 1547 (aged 43) Piacenza, Duchy of Parma and Piacenza |
| Spouse | Gerolama Orsini |
| Issue | |
| House | Farnese |
| Father | Pope Paul III |
| Mother | Silvia Ruffini |
Pier Luigi Farnese (19 November 1503 – 10 September 1547) was the first Duke of Castro from 1537 to 1545 and the first Duke of Parma and Piacenza from 1545 to 1547. He was the illegitimate son of Cardinal Alessandro Farnese (who later became Pope Paul III). He became a soldier and participated in the sack of Rome in 1527.