| Jurisdiction: | Diocese |
| Helsinki | |
| Latin: | Dioecesis Helsinkiensis |
| Local: | Helsingin hiippakunta (Finnish) Helsingfors stift (Swedish) |
| Coat: | Coat of arms of the Diocese of Helsinki.svg |
| Coat Size: | frameless |
| Country: |  Finland |
| Territory: | All Finland |
| Metropolitan: | Immediately subject to the Holy See |
| Coordinates: | 60.1592°N 24.9544°W |
| Area Km2: | 338,424 |
| Population: | 5,501,267 |
| Population As Of: | 2018 |
| Catholics: | 15,000[1] |
| Catholics Percent: | 0.2 |
| Parishes: | 8 |
| Denomination: | Catholic |
| Sui Iuris Church: | Latin Church |
| Rite: | Roman Rite |
| Established: | 1920 Established as Vicariate Apostolic of Finland; 1955 Erected as Diocese of Helsinki |
| Cathedral: | St. Henry's Cathedral |
| Priests: | 30 |
| Bishop: | Raimo Goyarrola |
| Bishop Title: | Bishop |
| Map: | Location of Helsinki in Finland.png |
The Diocese of Helsinki (Latin: Dioecesis Helsinkiensis) is a Latin Church diocese of the Catholic Church based in Helsinki, which comprises the whole of Finland. The diocese is divided into eight parishes. As of 2018, there are 15,000 registered and 10,000 unregistered Catholics living in Finland. There are more than 6,000 Catholic families in the country; 50 percent are Finnish and 50 percent are of international origin.
Bishop Raimo Goyarrola of Spain was chosen by Pope Francis to lead the diocese in September 2023.[2] The bishopric was vacant from May 2019 when Bishop Teemu Sippo resigned due to poor health.[3]
There is a high demand for starting a new parish at Northern Finland at Rovaniemi as it is the major tourist destination for Lapland and Santa Claus.
In 1550, the episcopate of the last Roman Catholic bishop of Åbo ended. Thereafter Lutheranism prevailed in Finland. The Reformation in the sixteenth century caused the loss of almost all of Northern Europe from the Roman Catholic Church. In 1582 the stray Catholics in Finland and elsewhere in Northern Europe were placed under the jurisdiction of a papal nuncio in Cologne. The Congregation de propaganda fide, on its establishment in 1622, took charge of the vast missionary field, which - at its third session - it divided among the nuncio of Brussels (for the Catholics in Denmark and Norway), the nuncio at Cologne (much of Northern Germany) and the nuncio to Poland (Finland, Mecklenburg, and Sweden).
In 1688, Finland became part of the Apostolic Vicariate of the Nordic Missions. In 1783, the Apostolic Vicariate of Sweden was created out of parts of the Nordic Missions comprising then Finland and Sweden. In 1809, when Finland came under Russian rule, the Roman Catholic jurisdiction passed on to the Metropolitan Archdiocese of Mohilev (then seated in St. Petersburg). In 1920, the Vatican established the Apostolic Vicariate of Finland which was upgraded to the Diocese of Helsinki in 1955.