Mo Church was built by Master Builder Erik Holten from Bæverdalen in 1728 using cog jointed, round timber. The main level is Y-shaped with an equilateral triangle in the middle and a square on each side. Ten Y-shaped churches was buit in Norway during the period 1663-1753, but several more may have been built. Both in the structure and idea, Y-shaped churches represented a unique and distinctly Norwegian architectural style. Five of the T-shaped churses are still in use: Rennebu Church (1669), Holmestrand Church (1674), Tydal Church (1696), Mo Church (1728) and Budal Church (1753). The other five have been pulled down.
Stave Church, dating from around 1500, was pulled down to make way for the new Y-shaped church. Some of the fixtures and fittings from the Stave Church were moved to the new church: the Church bell, cast in Holland in 1650, a two-armed brass candlestick and also plaque in memory of King Christian V's visit to Surnadal i 1685. The plaque describes the King's visit to the estate of Røv (formely known as Røwe) in the following verse:
Kong Christian den femte god
paa Røwe lod sig finde
Ret naadig mild i Sind og Mod
mod Mand saavel som Quinde
(Loosely translated: During his visit to Røv, good King Christian V was graciously mild in manner and mood to men and and women alike)
In 1931, a stone-covered grave, dating fro around the latter half of the 10th century, was found in the churchyard. In 1994, a boat grave, dating from the first of the 10th century was also found in the churchyard. In 2003, an old heart was found under the church floor. This may indicate that the area has been a place of ritual before arrival of Christianity.
The altarpiece was a gift from Vicar Søren Hagerup in 1767. No one knows for sure who the original artist was, but probably it must have been Ole Joensen Kolset (born 1722) from Kristiansund, who had painted and carved the altarpiece in Mo Church. In 1867 the altaepiece was painted over and altered somewhat. Ola Kattem, parish clerk and teacher, toned down the colorful wood carvings with white paint to save the alterpiece in the church. Expect for the male figures, most of the wood carvings were painted white so that the congregation would not be distracted from hearing Words of God.
In 1957, Ola Seter removed the white paint and restored the original colours, as far as was possible. He concluded that the tree paintings in the middle of the altarpiece were probably the work of Kattem and that this area had previously contained carved out images. The altarpiece was restored in 1983 and 1996 by restores from the Norwegian Directorate of Cultural Heritage, as the numerous layers of paint have tendency to crack and flake. In 1996, the altarpiece was seriously damaged when the sprinkler system was triggered.
During the Reformation, the King turned landed property into crown land, which was eventually lased out to private speculators. following the great Nordic War (1700-1720), King Fredrik IV was so har-up for cash that he sold the churches in Norway to raise money for the Treasury. Mo Church was privately owned up to 1862, when it was bought by the congregation of Mosokna Church for 150 "spesidalar". The private owners had saved om maintenance, so the church was rather run down when it was taken over. Both the roof and the outer cladding were in bad condition. major repairs were carried out in 1867-1868. The church was given a new gallery behind the altarpiece, a new pulpit and new, high windows. the old baroque pulpit was given to the museum in Kristiansund, where it was destryoed in a fire following an air raid in 1940.
Electric lightning was installed in the church in 1952, the same year as the baptistery was built. The organ, which dates from 1966, was the third in the church and did not work properly for many years. In 2004, it was replaced with a second-hand baroque organ, built by Gebrüder Reil in Netherlands in 1987. The organ has 11 stops and two manuals and one pedal. The organ was paid for through private donations.