The oldest sections of Finnekumla kyrka are thought to date from the twelfth century, and the church has been rebuilt and extended more than once since then. The most significant transformation came in 1850–1851, when the building was given its present Empire-style appearance: a sacristy was added, the windows on the south side enlarged, and the nave itself lengthened. Separate galleries for men and women were replaced by a single shared gallery reached from the porch. The timber bell tower was raised in 1855.
One of the church's most notable furnishings is its sandstone font, carved in two parts during the twelfth century by the stonemason Andreas. He is one of the few medieval font-carvers known to us by name, since he signed his work in runic script on the font's base — a rare and charming survival. The font was given to Gothenburg City Museum in 1876 but was returned to the church in 1920.
When the roof was replaced in the nineteenth century, the older painted ceiling boards were removed; some were reused for new flooring, while others reportedly remain hidden in the tower, behind the large medieval church bell — itself an unmarked example of a common late-medieval type.
Among the church's smaller treasures is a seventeenth-century money chest fitted with two locks, requiring two churchwardens to be present together before it could be opened — an early form of dual-key security. There is also an eighteenth-century measurement gauge, once used by parishioners and travelling traders to check that their ell- and foot-measures were accurate.
The gilded wooden cross on display was acquired around 1855; it stood on the altar until 1980, when it was moved to the north wall of the chancel, revealing the painted-glass chancel window installed in 1929. According to local tradition, a crucifix on the altar was donated by Countess Signe Sparre, and she and her husband Carl Georg Sparre are said to be buried in the churchyard just east of the church, together with their daughter, the author Birgit Th. Sparre.