The Impero is a 22.4-kilometre (13.9 mi) stream of Liguria (Italy).

The Impero rises near Monte Grande,[3] crosses the comunes of Aurigo, Borgomaro, Lucinasco, Chiusavecchia, Chiusanico and Pontedassio, giving its name to its valley, and ends in the Ligurian Sea in Oneglia (IM).

Impero basin (95 km2) is totally included in the Province of Imperia and also encompasses the communes of Cesio and Caravonica.

[4] Upstream of the village of San Lazzaro Reale (Borgomaro) the Impero (sometimes referred as Maro in this stretch) receives the following tributaries: The Tresenda (or Trexenda) is the main tributary of the Impero; it rises with the name of rio Caravonica from monte Mucchio di Pietre and gets from its right bank Rio Bramoso and Rio Acquafredda.

[5] Downstream San Lazzaro Reale, where it gets Tresenda waters, the Impero receives the following streams:[6] The Impero is not considered very interesting for fishing; upstream of Borgomaro trout coexist with cyprinids, while downstream the latter totally outnumber other fishes.