Sankt Johann in der Haide is situated at an elevation of 390 m in eastern Styria, close to the border to the province of Burgenland. The place was first mentioned as Rudegersdorf in 1147.The name was changed to that of the patron saint of the parish in the 15th century.
The parish church Johannes der Täufer (St. John the Baptist) was first mentioned in a document in 1452. The current church was built in 1775. It became parish church in 1784.