| Sant'Alessio con Vialone | |
| Official Name: | Comune di Sant'Alessio con Vialone |
| Coordinates: | 45.2167°N 24°W |
| Region: | Lombardy |
| Province: | Pavia (PV) |
| Frazioni: | Ca' de' Zetti, Vialone |
| Mayor: | Alberto Rusmini |
| Area Total Km2: | 6.56 |
| Population Total: | 951 |
| Population As Of: | 31 December 2014[1] |
| Population Demonym: | Santalessini |
| Elevation M: | 83 |
| Postal Code: | 27016 |
| Area Code: | 0382 |
Sant'Alessio con Vialone is a comune (municipality) in the Province of Pavia in the Italian region Lombardy, located about 30 km south of Milan and about 9 km northeast of Pavia.
Sights include the eponymous castle and the annexed natural preserve.