 On January 1, 2000, the name was changed from "Municipal District of Cardston No.6" to "Cardston County"

In the 2016 Census of Population conducted by Statistics Canada, Cardston County recorded a population of 4,481 living in 1,043 of its 1,260 total private dwellings, a change from its 2011 population of 4,167.With a land area of , it had a population density of in 2016.