Castelpizzuto is a comune, or municipality, located in the Province of Isernia within the Italian region of Molise. It is situated approximately 30 kilometres (19 mi) west of Campobasso and about 11 kilometres (7 mi) southeast of Isernia.
As of December 31, 2004, the municipality covered an area of 15.2 square kilometres (5.9 mi2) with a recorded population of 156 residents.