The church is thought to date from the second half of the twelfth century, with the nave possibly completed in the early thirteenth century. It began as a Romanesque stone building with a rectangular nave and a narrower chancel; its original eastern termination is unknown. A large stone partly built into the south-west corner of the nave may be a reused thirteenth-century coffin lid, though this remains uncertain.
The most striking exterior feature is the timber west tower, built in the 1670s or 1680s and completed by 1685. It rises above the nave roof in an octagonal, white-painted upper stage crowned with a copper-clad pyramidal cap and gilded cross. A major rebuilding in 1706 extended the church eastward, raised the walls, and replaced the ceiling with the barrel vault seen today.
Inside, the barrel-vaulted wooden ceiling is almost entirely covered with dark painted scenes: the Trinity above the chancel, the Last Judgement over the nave, and a depiction of Hell above the gallery, along with scenes from the life of Moses. These paintings were created in 1743 by Lars Holm of Gothenburg, with the Trinity motif over the chancel repainted in 1905 by Martin Bernhard Wallström, overlaying Holm's original work. The whole ceiling was conserved in 1955.
The carved, painted and gilded pulpit dates from 1627, the work of Svend Snedker of Marstrand, and features panels depicting the Evangelists and figures representing the four virtues. The altarpiece, a Baroque composition assembled from older parts and reworked by Wallström in 1905, shows the Virgin Mary and John the Baptist at the foot of the crucified Christ, flanked by carved angels. A separate medieval font, carved from a single block of gneiss and dated to the first half of the thirteenth century, stands in the chancel; a fourteenth-century oak triumphal crucifix, once mounted on the former chancel arch, now hangs on the south wall of the nave and is said to resemble one in Öckerö old church.
The church has been altered repeatedly since the eighteenth century, notably in 1858, 1905, 1955 and again in 2013, when the ceiling paintings were cleaned, pews were replaced with chairs, and the altar rail was divided into movable sections to allow flexible use of the space for concerts and services. The large bell is said to have been cast in Wismar in 1567 and may have come to Romelanda from Bergum church in the seventeenth century as a result of the Swedish–Norwegian wars, though this transfer is not firmly documented.