The history of Porvoo Cathedral dates back to the 13th century, when Porvoo was just a small trading post without city rights. Despite its modest beginnings, a stone church was constructed around the turn of the 13th and 14th centuries. As the town grew, the need to expand the church became necessary.

Between 1414 and 1418, the construction of Porvoo Cathedral was finally completed. The massive undertaking was likely led by the renowned master builder Carsten Nubuhr from Rostock.

In 1723, the cathedral became a bishop’s church when the Episcopal See was moved from Vyborg to Porvoo after the Great Northern War.

Throughout its history, the church has endured many hardships. It was ravaged by fire in 1508, 1571, 1590, and 1708. During the Continuation War in 1941, a bomb struck the church. The most recent fire occurred on 29 May 2006, when it fell victim to arson. The damage was repaired between 2006 and 2008, and the church was reopened on 30 November 2008.