The oldest parts of the nave probably date from the 13th century, making Spannarp one of Halland's older church sites. Its medieval appearance was largely lost, however, following a major rebuilding between 1821 and 1824: the church was extended eastwards, a semicircular chancel was added, the porch was removed, new windows were installed and a new west entrance opened. An earlier alteration in 1771 had already given the roof its broken profile.
The tower at the west gable dates from 1858–59, when it replaced an older wooden bell-frame with a stone tower built in the same style as the nave, distinguished by a band of brick near its top. The building material throughout is whitewashed granite.
Inside, the pulpit is a notable survival from 1673, carved in oak and pine, with painted panels on each side of the pulpit basket depicting the Old Testament prophets Isaiah, Jeremiah, Ezekiel and Daniel; its canopy and stair rail were added in 1901. The altarpiece, also in oak, dates from the same year, 1673, and is richly carved with the Institution of the Lord's Supper as its central theme. The font is from 1901, with a baptismal bowl added in 1927.
The church bells reflect changes over three centuries: the larger bell was recast in 1972, while the smaller bell dates from 1694 and is among the older furnishings retained in the building.
The organ case on the gallery dates from 1865, built by J. F. Ahlstrand of Istorp, though the instrument behind it has been replaced and rebuilt more than once, most recently in 1972.