The most populous county in Michigan in 2019 is Wayne County, home to Detroit, with a population of 1,753,616. This represents a growth rate of -3.39% since the 2010 census. Michigan is home to three other counties with more than 500,000 residents: Oakland (1,250,836), Macomb County (871,375), and Kent County (648,594). Of these, Kent County has experienced the highest population growth rate of 7.58%.
The least populous county in Michigan is Keweenaw County with a population of just 2,105, a growth rate of -2.95%. Michigan is home to 8 counties with a population of less than 10,000. Other small Michigan counties include Ontonagon County (5,881), Luce County (6,358), Schoolcraft County (8,049), Oscoda County (8,287), and Baraga County (8,441). All of these counties have experienced a decline in population. Ontonagon County has experienced the most dramatic population growth of -13.21%.
Ottawa County, the 8th largest county in Michigan, has experienced the largest population growth in Michigan at 8.44% since the census, bringing its population to 286,383. After Ottawa County, other counties that have experienced rapid growth include Kent County (7.58%), Washtenaw County (6.40%), and Grand Traverse County (5.56%). The county with the largest decline in population is Ontonagon County with a drop of 13.21%.