The Diocese of Vinh () is a Roman Catholic diocese in central Vietnam. The Most Reverend Alphonse NguyỠn Hữu Long was appointed bishop on December 22, 2018.
The diocese covers an area of 16,499 km<sup>2</sup>, and is a suffragan diocese of the Archdiocese of Hanoi.
Assumption Cathedral at Xã ÃÂoài in Nghi Diên commune is the cathedral of the diocese.
The circuit (trấn) of was evangelized by Jesuit missionaries as early as in 1629, especially by Girolamo Maiorica. After the Apostolic Vicariate of Tonkin (ÃÂàng Ngoài) was created in 1659, MEP missionaries were assigned to Nghá» An trấn. In 1846, the Vicariate of South Tonkin (Nam ÃÂàng Ngoài) was established, covering the area of Nghá» An and HàTénh provinces as well as northern Quảng Bình province. It has been renamed Vinh in 1924 and elevated to a diocese in 1960. In 2006, the other part of Quảng Bình province, south of Gianh River and Son River, was officially transferred from Archdiocese of Huế to the Diocese of Vinh after decades under Vinh's de facto supervision following the Partition of Vietnam. After being split to establish the Diocese of HàTénh in 2018, the Diocese of Vinh currently covers Nghá» An Province only.