The present church was built between 1770 and 1775 by the diocesan master builders Daniel Hagman and Per Hagmansson of Sundsvall, replacing an earlier cruciform stone church dedicated to Saint Olof that had stood on the site since the 1100s. According to an account recorded shortly before its demolition, that earlier church was said to be the only cross-shaped stone church of its kind in the country, built of smooth limestone, and its unusual status has led to theories that the archbishop himself may have been responsible for its construction. The site also lay on a pilgrim route running from Selånger to Nidaros.
Inside, the altar structure and pulpit were made by Johan Edler in the Gustavian style in the years following the church's 1775 consecration; the pulpit, completed in 1786, depicts Jesus and the sleeping disciples at Gethsemane. Behind the altar is a painted architectural perspective with gilding, added around 1790–92. The altarpiece itself is attributed to the Jämtland artist Pehr Sundin and is said to have been donated around 1800. Both entrance doors show carved rococo tendrils and angel heads. Among the older furnishings, a sandstone font attributed to the Gotland master Sighraf, active around 1170–1215, survives from the medieval church that once stood here.
The most distinctive feature at Brunflo is the kastal beside the church, a stone tower dated to the later part of the 1100s, roughly 16.5 metres high with a 9 by 9 metre base and a later wooden cap. Such towers are very rare in northern Sweden, and this is one of only two known in Jämtland, the other being a partly ruined example at Sunne church; their presence suggests that the district held considerable importance in the Middle Ages. The kastal is thought to have served as a storehouse for goods and taxes in kind owed to the archbishop, as a defensive refuge in troubled times, and today houses the church bells, the oldest cast in Stockholm in 1665.
In the churchyard stands a gravestone dated 1704, raised in memory of a land surveyor who died suddenly in Brunflo in the 1640s.