The Mahlberg Castle Church is a jewel of the Rococo, one of the rare central buildings in the country. Its octagonal shape dates back to the Middle Ages, from the time of the Crusaders.
In 1734 it was given its baroque form. False vaults were added, and the decorative clock gable was erected. Three saints (Joseph, Catherine, James) remind us of the transience of life and the preciousness of the time we are given. The inner shell of the room was created in 1762: like an open columned hall, with valuable stucco, eight pictures from the life of Saint Catherine of Alexandria, the mighty alliance coat of arms of the House of Baden-Baden, whose officials resided in the castle until 1771 and whose red and gold colors still adorn the facade today. The original roof turret was replaced by a sandstone bell tower in 1890.
It was the state church until 1803. In the following year, the Evangelical Church of Mahlberg, which had existed until 1622 and whose members had subsequently been assigned to Kippenheim, regained its independence from the House of Baden-Durlach. The castle church was handed over to the Evangelicals.