| Mallero | |
| Source1: | Monte del Forno |
| Source1 Location: | north of Sondrio, Italy |
| Source1 Coordinates: | 46.3416°N 9.7319°W |
| Source1 Elevation: | 2750m (9,020feet) [1] |
| Mouth: | Adda |
| Mouth Location: | Sondrio |
| Mouth Coordinates: | 46.1611°N 9.8497°W |
| Subdivision Type1: | Countries |
| Subdivision Name1: | Italy |
| Length: | 30.3km (18.8miles) |
Mallero is a river in the Province of Sondrio.
Its source is near the Monte del Forno, it flows south through the Valmalenco and joins the Adda after crossing Sondrio. Towns along the river include Chiesa in Valmalenco, Torre di Santa Maria and Spriana.
Antognasco, Lanterna, Torreggio, Entovasco, Nevasco, Forasco, Pirola, Braciasco, Giumellini, Arcoglio, Dagua, Valdone.