Hagby Church, Round medieval church in Kalmar Municipality, Sweden

Hagby Church is a whitewashed round church with a tall conical shingled roof topped by a small spire. A small gabled porch with a dark roof stands on the left, and a lower round section with its own conical roof adjoins on the right. The drum has a small round window and narrow arched windows, and the church stands among grass and gravestones.

The stone church was built in the 13th century, sometimes linked to an earlier wooden chapel of Saint Sigfrid a few kilometres south, though that chapel is undated. Tradition holds it served as both sanctuary and fortification, with seventeen openings in the upper walls read as arrow slits, a defensive role questioned by recent research. A central tower, probably demolished in the 1660s, once divided the interior into two or three levels.

The church was dedicated to Saint Olaf in the Catholic era and has been the parish church of Hagby socken since the Middle Ages; it now serves the Arby-Hagby congregation in the Diocese of Växjö. A wooden crucifix from around 1500 hangs in the chancel apse, and a silver chalice and paten found under the floor in 1889 are now in the Swedish History Museum.

Visitors can explore the church to see its unusual round shape and examine the medieval architecture up close. The narrow openings in the thick walls are easy to spot and help you understand the defensive purpose these buildings once served.

The church is one of only eight surviving round churches in the country and displays a rare architectural form from the Middle Ages. This circular design was uncommon and shows how people combined religious worship with military defense in a single structure.