Rayside-Balfour, Ont, was incorporated as 2 separate townships in 1891; in 1973 all of Rayside township and part of Balfour township were merged to form the town of Rayside-Balfour. Rayside-Balfour is now part of the city of GREATER SUDBURY, the result of another amalgamation that also included the former towns of Capreol, Onaping Falls, Walden and Nickel Centre, and the former cities of Sudbury and VALLEY EAST.
Rayside was originally established as a railway community in the late 19th century. In 1891 a post office opened and the community was given the name St Azilda after Azilda Brisbois, an early resident. The name was later changed to Rayside when post office officials realized there was no saint by the name of Azilda. Rayside and Balfour were both named for members of the Ontario legislature: James Rayside and William Douglas Balfour.
In the 1890s Rayside and Balfour enjoyed a boom in mining development, and vestiges of abandoned mines are still common in the area. In the 1920s and 1930s lead and zinc smelters operated in Balfour Township. When the mining industry waned, agriculture became the economic mainstay.