| Jurisdiction: | Archdiocese |
| Bangkok | |
| Latin: | Archidiœcesis Bangkokensis |
| Local: | อัครสังฆมณฑลกรุงเทพฯ |
| Country: |  Thailand |
| Territory: | Bangkok |
| Area Km2: | 18,831 |
| Population: | 13,226,721 |
| Population As Of: | 2012 |
| Catholics: | 115,945 |
| Catholics Percent: | 0.9 |
| Parishes: | 54 |
| Denomination: | Catholic |
| Sui Iuris Church: | Latin Church |
| Rite: | Roman Rite |
| Established: | December 18, 1965 |
| Cathedral: | Assumption Cathedral, Bangkok |
| Bishop: | Sede vacante |
| Bishop Title: | Archbishop |
| Apostolic Admin: | Francis Xavier Vira Arpondratana |
| Emeritus Bishops: | Michael Michai Kitbunchu Francis Xavier Kriengsak Kovithavanij |
| Map: | Thailand Diocese Bangkok.png |
The Roman Catholic Archdiocese of Bangkok (Latin: Archidiœcesis Bangkokensis, Thai: อัครสังฆมณฑลกรุงเทพฯ) is a Latin archdiocese in Thailand. The bishop's seat is the Assumption Cathedral, Bangkok.
In 1662, the Apostolic Vicariate of Siam was created [1] [2] on territory split off from the Apostolic Vicariate of Cochinchina, based in Vietnam. It was renamed the Apostolic Vicariate of Eastern Siam[2] on 10 September 1841, having lost territory to establish the Apostolic Vicariate of Western Siam. On 5 May 1899 it lost more territory to establish the Apostolic Vicariate of Laos.
It was renamed the Apostolic Vicariate of Bangkok[2] on 3 December 1924.
It lost more territories: on 30 June 1930 to establish the Mission sui juris of Rajaburi, on 11 May 1944 to establish the Apostolic Vicariate of Chantaburi and on 17 November 1959 to establish the Apostolic Prefecture of Chieng-Mai. All three of these have become its suffragans. On 18 December 1965, it was elevated to the rank of a Metropolitan archdiocese.
On 9 February 1967 it lost territory to establish the Diocese of Nakhon Sawan as its suffragan.
It was visited by Pope John Paul II in May 1984 and Pope Francis in November 2019.
The archdiocese covers an area of 18,831 km2, and as of 2002 it is responsible for 81,646 Catholic Christians, 0.7% of the about 12 million living in the area. It covers the administrative provinces Ayutthaya, Bangkok, Nakhon Pathom, Nonthaburi, Pathum Thani, Samut Prakan, Samut Sakhon and Suphanburi; also the parts west of the Bang Pa Kong River of Chachoengsao and Ban Na of Nakhon Nayok belong to the diocese.
Its ecclesiastical province comprises the Metropolitan's own archdiocese and these five suffragan bishoprics :