Porvoo Parish likely dates back to the late 13th century. The oldest part of the present greystone church was built in the late 13th or early 14th century.

In the early 15th century, the church was rebuilt and enlarged. With its ornamented brick gables, it resembles medieval stone churches in Pernaja and Sipoo.

Parts of the original structure remain in the west gable and on the north side. However, no artifacts from the earliest period have survived, as the church has been plundered and burned multiple times.

In 1508, Danish pirates ravaged the church. It was burned again during Russian attacks in 1571 and 1590. King Gustav Vasa confiscated church valuables, sending them to the Royal Palace in Stockholm.

The church was rebuilt in the 17th century but was again burned to the ground in 1708 during the Great Northern War. Some vaults in the middle and south nave collapsed, explaining the absence of medieval paintings in these areas.

Porvoo Church became a cathedral in 1723 when the Episcopal See moved from Vyborg to Porvoo. In 1923, a Swedish Diocese was established, making Porvoo Cathedral the diocesan seat.

The cathedral also suffered damage in the 20th century. In 1941, a bomb fell through the roof and exploded under the floor but caused no further destruction.

The existing galleries were built in the 1760s. The church underwent major renovations in the 1950s, followed by additional restoration in 1977–78, during which the gallery fronts and pulpit were restored to their original verdigris color after being painted white and gold for a century.

On 29 May 2006, arson destroyed the cathedral’s roof structures, causing extensive water and smoke damage. Chandeliers from the 18th and 19th centuries were severely damaged when they fell onto the stone floor. The cathedral was closed for two years for restoration and reopened on 30 November 2008.

Today, the cathedral serves both the Swedish- and Finnish-speaking parishes of Porvoo.