| Retegno | |
| Coordinates: | 45.15°N 50°W |
| Region: | Lombardy |
| Province: | Province of Lodi (LO) |
| Comune: | Fombio |
| Postal Code: | 26861 |
| Area Code: | 0377 |
Retegno is a small town within the municipality of Fombio, Lombardy, Italy.
Retegno had been Imperial Baronia and a Fief of Trivulzio family.