Ostiano is a comune (municipality) in the Province of Cremona in the Italian region Lombardy, located about southeast of Milan and about northeast of Cremona. As of 31 December 2004, it had a population of 3,054 and an area of .
Ostiano borders the following municipalities: Gabbioneta-Binanuova, Gambara, Pessina Cremonese, Pralboino, Seniga, Volongo.
Among the churches in the territory are:
- Oratory of the Disciplini
- Pieve di San Gaudenzio former abbey church
- San Michele Arcangelo parish church
- Chiesa di Torricella Romanesque oratory