In the 2021 Census of Population conducted by Statistics Canada, Red Deer County had a population of 19,933 living in 7,430 of its 8,674 total private dwellings, a change of 2.1% from its 2016 population of 19,531. With a land area of 3,919.25 km (1,513.23 sq mi), it had a population density of 5.1/km (13.2/sq mi) in 2021.
In the 2016 Census of Population conducted by Statistics Canada, Red Deer County had a population of 19,541 living in 7,097 of its 8,440 total private dwellings, a 6.7% change from its 2011 population of 18,316. With a land area of 3,961.85 km (1,529.68 sq mi), it had a population density of 4.9/km (12.8/sq mi) in 2016.
Agriculture plays a role in Red Deer County's economy including livestock and crop production. Red Deer County has dairies that make cheese, U-pick vegetable and fruit farms, and the largest organic farm in Alberta. It also has elk, deer, and apiary farms as well as a mouse farm, which raises white mice for the pet food industry. Lumber and mineral resources are also present in Red Deer County.