Montiglio Monferrato is a comune in the Province of Asti in the Italian region Piedmont, located in the Valle Versa about 30 kilometres (19 mi) east of Turin and about 20 kilometres (12 mi) northwest of Asti.

The fourth principal population centre is the village of Rinco; this also was a commune in its own right until 1916 when it was absorbed by Scandeluzza.

The castle's park houses the Chapel of St. Andrew, with the largest cycle of 14th-century frescoes in Piedmont.

The 18th-century town church in via Roma features frescoes by Pietro Ivaldi.

The 17th-century church of San Rocco is found in Piazza Umberto.