Riva Valdobbia (Walser German: Riifu, Piedmontese: La Riva) is a fraction in the Province of Vercelli in the Italian region Piedmont, located about 90 kilometres (56 mi) north of Turin and about 70 kilometres (43 mi) northwest of Vercelli. It's an Italian town of 265 inhabitants located in the upper Valsesia, in the province of Vercelli, in Piedmont.

From 1 January 2019 it ceased to exist for the incorporation in the neighboring municipality of Alagna Valsesia.

The fraction of Riva Valdobbia is near the end of the Valsesia, the main Sesia Valley. It is a touristic place with a cross-country ski ring and an ice car track during the winter.

It is known to be the only town where the south-east side of the Monte Rosa.