Population of Counties in Illinois (2018)

Name 2018 Population Growth Rate
Cook County5,231,3560.61%
DuPage County931,1531.42%
Lake County704,9350.09%
Will County689,7311.61%
Kane County532,5533.18%
McHenry County307,972-0.35%
Winnebago County286,088-3.05%
Madison County265,598-1.39%
St. Clair County263,120-2.67%
Champaign County209,2673.83%
Sangamon County197,591-0.09%
Peoria County185,296-0.50%
McLean County172,6881.70%
Rock Island County145,472-1.45%
Tazewell County133,967-1.12%
Kendall County124,5737.97%
LaSalle County110,507-2.91%
Kankakee County110,053-2.97%
Macon County106,651-3.72%
DeKalb County104,447-0.67%
Vermilion County78,560-3.77%
Williamson County67,6401.82%
Adams County66,673-0.73%
Jackson County59,032-2.24%
Whiteside County56,541-3.32%
Boone County53,562-1.01%
Coles County52,412-2.70%
Ogle County51,168-4.22%
Knox County50,945-3.70%
Grundy County50,2690.24%
Henry County49,524-1.84%
Macoupin County45,653-4.49%
Stephenson County45,540-4.34%
Franklin County39,092-2.34%
Woodford County38,9330.68%
Jefferson County38,308-1.16%
Marion County38,066-3.43%
Clinton County37,565-0.73%
Livingston County36,475-6.13%
Fulton County35,517-4.20%
Lee County34,399-4.38%
Morgan County34,194-3.71%
Effingham County34,182-0.11%
Monroe County33,8782.65%
Bureau County33,433-4.36%
Christian County33,271-4.31%
Randolph County32,597-2.58%
McDonough County31,387-3.81%
Logan County29,338-3.11%
Montgomery County29,079-3.37%
Iroquois County28,214-5.00%
Saline County24,253-2.60%
Jersey County21,945-4.46%
Jo Daviess County21,861-3.46%
Fayette County21,816-1.42%
Shelby County21,727-2.84%
Perry County21,382-4.20%
Douglas County19,769-1.09%
Crawford County19,142-3.33%
Hancock County18,219-4.57%
Edgar County17,472-5.59%
Warren County17,307-2.33%
Union County17,115-3.49%
Bond County16,841-5.32%
Wayne County16,573-0.99%
Piatt County16,526-1.11%
Lawrence County16,343-3.52%
De Witt County16,159-2.62%
Pike County15,882-3.12%
Richland County15,858-2.07%
Clark County15,848-2.72%
Mercer County15,630-4.75%
Carroll County14,611-5.06%
Moultrie County14,599-1.72%
Massac County14,469-5.91%
Washington County14,210-3.41%
White County14,088-3.51%
Mason County13,706-6.45%
Ford County13,342-5.25%
Clay County13,311-3.72%
Greene County13,119-5.55%
Johnson County12,9612.79%
Cass County12,681-7.00%
Menard County12,399-2.34%
Marshall County11,898-5.80%
Wabash County11,511-3.40%
Cumberland County10,892-1.48%
Jasper County9,593-1.33%
Hamilton County8,199-2.92%
Schuyler County7,053-6.40%
Henderson County6,874-6.39%
Brown County6,744-2.53%
Edwards County6,545-2.81%
Alexander County6,491-20.90%
Putnam County5,717-4.91%
Pulaski County5,603-8.54%
Stark County5,506-7.80%
Gallatin County5,163-7.37%
Scott County5,055-5.11%
Calhoun County4,859-4.65%
Pope County4,295-3.91%
Hardin County4,099-5.01%