The church's oldest masonry, built of rough stone, dates from the late 1200s or early 1300s, and survives mainly in the northern walls of the nave and the oldest parts of the sacristy. The building reached its present form in the 1480s, when it was remodelled as a three-aisled hall church with Gothic star vaults over the nave and cross vaults over the side aisles, resting on octagonal pillars. The three-sided chancel was added in 1754 with its own domed cross vaulting.
The church's unusually large size reflects its medieval role as the mother church for almost the whole of northern Dalarna, a vast parish that only gradually broke up into smaller congregations. In the Middle Ages the church was dedicated to Saint Michael, which is why the archangel still appears on Mora's municipal coat of arms.
The porch on the south side, built around 1500 shortly after the nave, has a richly decorated brick gable with blind arcading and corner banding, and served for a long time as the main entrance. The heavy tower with its tall spire was raised in 1581, partly obscuring an earlier ornamented brick west front that can still be glimpsed inside the tower room and porch. A lightning strike on 3 May 1671, according to one source, caused a serious fire that destroyed the roofs and the entire tower. Rebuilding of the roof was swift, reportedly thanks to the parish priest's connections at court, which secured royal backing for a new tower design attributed to the architect Jean de la Vallée. The tower itself was not finished until 1673, so in the meantime a freestanding wooden bell tower was erected beside the church, said to have been built in 1672 by a local craftsman; it received a copper roof in the 1830s and appears in the background of Anders Zorn's painting of Mora market.
A major restoration in 1895 saw the exterior walls rendered and some windows given a neo-Gothic treatment. Further restoration in 1964–65 strengthened the vaults and uncovered fragments of sixteenth-century wall paintings in the north aisle, remnants of decoration that once covered the whole church.
The church has had a succession of organs, including an early instrument from 1585 and a large early twentieth-century organ later relocated to Poland; the current main organ dates from 1967, alongside a smaller choir organ.