Tucked into the rolling landscape of Foothills County in southern Alberta, Aldersyde sits between Highway 2 and Highway 2A, just south of Highway 7. The hamlet lies roughly 8 kilometres southeast of Okotoks, 10 kilometres north of High River, and about 25 kilometres south of Calgary, placing it at a convenient crossroads between several of the region’s better-known communities.
The area has a long human history, with a prehistoric tipi ring identified nearby during a 1986 archaeological survey, pointing to the presence of Indigenous peoples long before European settlement. The community began as a settlement called Norma around 1889, but shifted to its current location in 1893 after a Canadian Pacific Railway line was established there. What remained of the original Norma settlement was destroyed by fire shortly after, and its surviving residents joined the growing community at the new site. The townsite took on the name Aldersyde by 1907, when settler Elias Bricker opened a post office inside a local general store. The origins of that name are somewhat disputed: some trace it to a place in Scotland, others to a fictitious location in an 1883 novel by Scottish writer Annie Swan, while a 1937 report in the Calgary Herald credited J. D. O’Neal, on whose land the hamlet was built, saying he named it after the abundance of alder trees in the area. Early landmarks included the Mount View Mennonite Church, which opened around 1901 or 1902, and the Maple Leaf School, established in 1903. In 1911, a rail connection to Lethbridge and Vulcan via the Kipp-Aldersyde line further linked the community to the broader region. The school closed in 1953 and was later converted into a community hall by the Aldersyde Community Association in 1956. The church closed in 1974, and was converted into a private residence, while the affiliated cemetery passed into the care of the Trinity Mennonite Church of Calgary and remains in use as of 2021. Aldersyde was formally designated a hamlet in 1980. A brief industrial chapter unfolded in February 1990 when the Magnesium Company of Canada opened a smelting plant there, bringing 145 jobs to the area, though declining magnesium prices led to its closure just one year later in February 1991, and the abandoned facility remained standing outside the hamlet as of 2018.