The Staffora is a river of the Oltrepò Pavese in the Province of Pavia, north-west Italy and a right-side tributary of the Po.

The Staffora then passes through the eastern outskirts of Voghera, the principal town on its course, before entering the Po near Cervesina.

Although the river flows throughout the year, fed by perennial springs as well as by seasonal rains and melting ice, the regime is torrential: its discharge can vary between 0.7 and 675 cubic metres per second (25 and 23,837 cu ft/s) The river is usually identified with the Roman Iria, following the derivation of ‘Voghera’, which lies on the left bank of the Staffora, from Vicus Iria.

The Roman Emperor Majorian was beheaded on the 7th of August 461 AD, after 5 days of torture by his Magister Militum Ricimer, near the river.

The word ‘Stàffora’, once ‘Stàfula’, comes from the Lombard "Staffel", which first referred to a place on the river's course near Voghera: cascina Stàffela.