Tradition holds that a wooden church or manor chapel stood on this site as early as the eleventh century, and it is said that Saint Sigfrid began his missionary work in the surrounding district of Södra Möre. A Romanesque stone church followed in the twelfth century, likely linked to a local estate, before being greatly enlarged around the end of the thirteenth century into one of the largest medieval churches in the Kalmar area. During the Middle Ages Ljungby served as the seat of the provost of Möre and maintained close ties to the bishopric of Linköping; later analysis of the masonry has suggested a relationship with the neighbouring church at Hossmo.
The building has suffered and been rebuilt more than once. Fire damaged the church in 1654, and a lightning strike in 1757 led to a thorough rebuilding, with the restored church reconsecrated by the bishop in 1767 as an almost entirely new structure; medieval vaults and pillars were replaced with wooden vaulting. Today's church consists of a rectangular nave with an eastern chancel and a western tower.
The present tower dates from an extensive renovation in 1857, which replaced an older bell tower from the late sixteenth century. That work was overseen by the architect Carl Georg Brunius, known for his restorations of Lund and Växjö cathedrals and his enthusiasm for medieval-inspired design; at Ljungby this is reflected in the stepped gables added to the tower, nave and chancel. A further renovation in 1988 altered the interior, converting the large chancel into a smaller worship space.
Built into the church's west gable since around 1860 is a fragment of a runestone, thought to date from the late eleventh or early twelfth century. Its inscription commemorates a man named Vinterlide, raised by two people whose names are recorded as Fet and Ragna. This stone is believed to have originally stood, along with others, on the very site where the church was later built.
From the seventeenth century Ljungby was a prebendal parish, its incumbency held by theology lecturers at the Kalmar gymnasium and, from 1830, by the bishops of Kalmar diocese, who served as titular vicars alongside their main duties. This arrangement ended with the bishop's death in 1913 and the merger of Kalmar diocese into Växjö diocese in 1915, after which the parish received its own resident vicar. Notable furnishings include a carved triumphal crucifix, a Neo-Gothic pulpit with sounding board added during the 1857 restoration, and an older altarpiece painted by Jonas Berggren in 1767, alongside a later altarpiece from 1924.