The Roman Catholic diocese of Bobbio was an Italian bishopric which existed from 1014 until 1986. The diocese was formed from the territory of the Abbey of Bobbio.

Bobbio Abbey is a monastery founded by Irish Saint Columbanus in 614, around which later grew up the town of Bobbio, in the province of Piacenza, Emilia-Romagna, Italy. It is dedicated to Saint Columbanus. It was famous as a centre of resistance to Arianism and as one of the greatest libraries in the Middle Ages. The abbey was dissolved under the French administration in 1803, although many of the buildings remain in other uses.