| Jurisdiction: | Diocese |
| Daejeon | |
| Latin: | Dioecesis Taeieonensis |
| Local: | 대전교구 |
| Territory: | Daejeon, Sejong and South Chungcheong |
| Province: | Seoul |
| Metropolitan: | Seoul |
| Area Km2: | 9,190 |
| Population: | 3,866,219 |
| Population As Of: | 2017 |
| Catholics: | 335,152 |
| Catholics Percent: | 8.5 |
| Parishes: | 142 |
| Denomination: | Catholic |
| Sui Iuris Church: | Latin Church |
| Rite: | Roman Rite |
| Established: | June 23, 1958 (years ago) |
| Cathedral: | Cathedral of St. Joseph the Worker in Daejeon |
| Patron: | Our Lady of Lourdes |
| Bishop: | Augustinus Kim Jong Soo |
| Bishop Title: | Bishop |
| Auxiliary Bishops: | Stephanus Han Jung-hyun |
| Map: | Diocese of Daejeon.svg |
The Roman Catholic Diocese of Daejeon (la|Dioecesis Taeieonensis, Hangul:) is a diocese of the Latin Church of the Catholic Church in South Korea. It is the diocese for Daejeon, South Korea. Augustinus Kim Jong-soo has been appointed its bishop; Stephanus Han Jung-hyun is auxiliary bishop.
On 23 June 1958 Pope Pius XII erected the apostolic vicariate of Daejeon. The vicariate was made a diocese on 10 March 1962 by Pope John XXIII.[1] [2]