The diocese of Bac Ninh (Latin: Dioecesis Bacninhensis) is a Roman Catholic diocese of Vietnam.

The creation of the diocese in present form was declared November 24, 1960.

The diocese covers an area of 12,227 km², and is a suffragan diocese of the Archdiocese of Hanoi.

By 2004, the diocese of Bac Ninh had about 123,090 believers (1.8% of the population), 23 priests and 47 parishes.

This article on a Roman Catholic diocese in Vietnam is a stub.