| Erro | |
| Source1 Location: | Monte Ermetta |
| Mouth Location: | Bormida at Terzo (AL) |
| Mouth Coordinates: | 44.6645°N 8.4297°W |
| Subdivision Type1: | Country |
| Mouth Elevation: | 222m (728feet) |
| Discharge1 Avg: | 4.6m3/s |
| Length: | 46.5km (28.9miles)[1] |
| Basin Size: | 246.9km2[2] |
| Map: | Erro location map.jpg |
The Erro (in Piedmontese Er) is a 46km (29miles) torrent of north-west Italy, a right tributary of the Bormida.
The river rises in the Ligurian Province of Savona at an elevation 1267m (4,157feet) on Monte Ermetta, to the west of Monte Beigua. Having passed through the territory of Sassello, the river enters the Piedmontese Province of Alessandria at Ponte Erro (Malvicino). Its course takes it past Cartosio, Rivere, Castelletto d'Erro, Arzello, and Melazzo before joining the Bormida at Terzo, a little upstream from Acqui Terme at an elevation of 222m (728feet).
The initial version of this article was a translation from, its counterpart in the Italian Wikipedia.