San Valentino Torio is a town and comune in the province of Salerno in the Campania region of south-west Italy.

San Valentino Torio is situated in the northern part of the province, not far from Mount Vesuvius, in the Sarno river valley.

The first traces of human presence in the southern plain of Campania date to the ninth through sixth centuries BCE.

The earliest mention of San Valentino (as Balentino) is from an 868 CE document, preserved in the Trinità della Cava abbey.

Its territory was held by the Del Balzo and Capece Minutolo families until the abolition of feudalism in 1806.