The Diocese of Vĩnh Long (Latin: Dioecesis Vinhlongensis) is a Roman Catholic diocese in southern Vietnam.

The current bishop is Peter Huỳnh Văn Hai, since October 2015.

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

By 2014, the diocese of Vĩnh Long had about 199,404 Catholics (4.5% of the population), 179 priests and 209 parishes.

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