Stadtpfarrkirche St. Johann church is located next to Rapperswil Castle. The castle and the parish church were built by Count Rudolf II and his son Rudolf III around 1220/29. The former parish church was located at Busskirch on upper Zürichsee lake shore, being one of the oldest churches around the lake area. Even the citizens of Rapperswil had to attend services in Busskirch until Count Rudolf II built his own parish church on he Herrenberg hill next to the castle. Legally, Rapperswil church was subordinated to 1253 the parish of St. Johann Busskirch and thus the Pfäfers abbey. In 1489 the adjacent Liebfrauenkapelle was built, the cemetery chapel that still exists. On 30 January 1881 the church was partially destroyed by fire, and rebuilt from 1881 to 1885.
The Romanesque hall church and the northern church tower were extended in 1383 to the west. In 1441 a smaller but massively southern church tower was built. Collection campaigns in 1493/97 allowed to rebuild the hall church into a tripartite Gothic choir with arched ceiling and tracery windows. Following the Reformation in Switzerland, two Renaissance wing altars in the side chapels were added respectively latter moved to other chappels. Thus, these altars were not destroyed by fire on January 30, 1882, as well as the sacristy located in the southern church tower, along with the precious treasure of the church: masterpieces by the goldsmiths Breny from Rapperswil, Dietrich, Dumeisen and Rüssi Ysenschlegel, being one of the richest in the Linth territory.
References:The first written record of church in Danmark locality date back to the year 1291. Close to the church are several stones with a Christian text and cross inscribed. The oldest parts of the present red-brick church are from the 1300s. In the late 1400s the church was enlarged to the appearance it has today. The church has been modified both internally and externally several times, among other things after the fires in 1699 and 1889. There are lot of well-preserved mural paintings in the walls.