 The second largest city is Lexington with a 2018 census population of 323,780, its metro had a population of 516,697, and its CSA, which includes the Frankfort and Richmond statistical areas, having a population of 746,310.The Northern Kentucky area, which comprises the seven Kentucky counties in the Cincinnati/Northern Kentucky metropolitan area, had a population of 447,457 in 2018.The metropolitan areas of Louisville, Lexington, and Northern Kentucky have a combined population of 2,402,958 , which is 54% of the state's total population on only about 19% of the state's land.