The Irati river (Basque: Iratiko erreka) is a right bank tributary of the Aragon in Sangüesa, Navarre.

After having fared through Aezkoa and Oroz-Betelu, offering stunning landscapes, the Irati is held up again in the marais d'Itoiz, already joined by the Urrobi and the Erro.

It is then joined by the Areta and the Salazar [es] to immediately enter the gorges of la Foz de Lumbier.

It is probably the most used river for hydro-electrical purposes, namely after the inauguration of Irati S.A enterprise (1911), which also gave its name to the electrical train from Pamplona to Sangüesa.

Along the river, one can still find a lot of tubes, buckets, pipes, canals and plants which reflect the quality of these constructions.