Tucked into the heart of central Alberta, Mirror sits at the intersection of Highway 50 and Highway 21, roughly 42 kilometres east of Lacombe and just over 52 kilometres northeast of Red Deer. The community falls under the jurisdiction of Lacombe County and covers a land area of 2.3 square kilometres. Its roots stretch back to 1870, though much of its early character was shaped by a nearby trading post called Lamerton, which began as the Buffalo Lake trading post in 1892. Lamerton grew steadily over the following years, developing a post office, a grocery and dry goods store, a livery barn, a hardware store, a blacksmith shop, a creamery, a church, and a hotel. When the Grand Trunk Pacific Railway could not secure land at Lamerton, it established its divisional point two miles to the south in 1911, and Mirror was born. Buildings, businesses, and residents from Lamerton relocated to the new town site throughout 1912, including a post office, hardware store, drug store, lumber yard, restaurant, the Imperial Hotel, two livery stables, two pool halls, and branches of the Bank of Commerce.
Mirror was incorporated as a village on July 12, 1912, a status it held for nearly a century before being dissolved and reorganised as a hamlet on January 1, 2004. According to the 2021 Census conducted by Statistics Canada, Mirror had a population of 481 people living in 253 of its 270 private dwellings, reflecting a modest decline of 4.2 percent from the 502 residents recorded in 2016. That 2016 figure itself represented a 7.3 percent increase over the 468 residents counted in 2011, suggesting the community has seen some variation in its population over recent census cycles. With its compact 2.3 square kilometre footprint, Mirror recorded a population density of approximately 209 people per square kilometre in 2021.