Roatto is a comune (municipality) in the Province of Asti in the Italian region Piedmont, located about southeast of Turin and about northwest of Asti. As of 31 December 2004, it had a population of 385 and an area of .
Roatto borders the following municipalities: Cortazzone, Maretto, Montafia, San Paolo Solbrito, and Villafranca d'Asti.
The municipality is part of the comunitÃÂ collinare Valtriversa.