Marion County, IL Population

Overview

37,781

Total Population

42.1

Median age

50.95%

Female population %

96.3:100

Gender ratio (M:F)

55-59 years

Largest age group

63.9

Total dependency ratio

White

Largest racial group

833

Hispanic population

Sources: U.S. Census Bureau, American Community Survey (ACS) 2021

TABLE OF CONTENTS

Age

Marion County's population is old compared to the rest of the country:

The median age in Marion County is 42.1, compared to 38.8 nationwide, according to the American Community Survey 2017 - 2021 5 Year estimates.
Marion County's population under 18 was 23.54%, compared to the 22.51% nationwide.
Marion County's elderly or the senior population (over 65 age) was 19.37% as compared to 16.04% nationwide.
Of the total population in Marion County, 19.61% were under the age of 15, 17.48% aged 15 to 29, 43.53% aged 30 to 64, 16.88% aged 65 to 84, and 2.50% were 85 years of age and older.

There are 721 more females than males in Marion County:

The female percentage in the USA is 50.50% while the male percentage is 49.50%, compared to 50.95% females and 49.05% males in Marion County, IL.
The Marion County, IL gender ratio is 96.3:100 i.e. 96.3 men to 100 women (0.963).
For male population, the largest age group is 5-9 years with a population of 1,343.
For the female population, the largest age group is 60-64 years with a population of 1,393.

Marion County's population has become increasingly diverse:

Racial distribution of Marion County population: 91.98% are White, 3.80% are Black or African American, 0.02% are American Indian and Alaska Native, 0.61% are Asian, 0.01% are Native Hawaiian and other Pacific Islander, 0.54% are some other race and 3.04% are multiracial.
Marion County's racial breakdown clearly shows that there is an absolute majority of White population in the county.
By ethnicity, 833 is Hispanic or Latino (of any race), and 36,948 (97.80% of the total population) is Non-Hispanic.
The largest racial group in Marion County is White with a population of 34,751 (91.98% of the total population).

Marion County's population has already reached its peak and is showing a trend of decline:

The peak population was 41,677 in the year 2000
From 2000 to 2010, Marion County's population decreased by 2,261 (5.43%), as compared to the national growth of 9.63%.
From 2010 to 2020, Marion County's population decreased by 1,777 (4.51%), according to Census Bureau's Population Estimates Program. For the same period, the rate of growth for the United States was 7.17%.
Between the year 2000 and 2022, Marion County's population was lowest in year 2022 at 36,914.