Monmouth Flag

Monmouth

County:
Warren County
County Seat:
Yes
Area (mi²):
36.831
State:
Illinois

Monmouth is located in Warren County, Illinois. Monmouth has a 2025 population of 9,365. It is also the county seat of Warren County. Monmouth is currently declining at a rate of -1.08% annually and its population has decreased by -5.76% since the most recent census, which recorded a population of 9,937 in 2020.

The average household income in Monmouth is $81,697 with a poverty rate of 15.17%.The median age in Monmouth is 35.8 years: 34.5 years for males, and 38.2 years for females.

9.4K
Total Population
254
Density (mi²)
-102 -1.08%
Growth

Monmouth Population

Monmouth Population

Data after 2023 is projected based on recent change

Demographics

The racial composition of Monmouth includes 77.25% White, 7.26% other race, 4.21% Black or African American, 3.64% Asian, and smaller percentages for Native American, Native Hawaiian or Pacific Islander and multiracial populations.

Population by Race

White (77.3%)

Other race (7.3%)

Two or more races (5.0%)

Black or African American (4.2%)

Asian (3.6%)

Native American (2.0%)

Native Hawaiian or Pacific Islander (0.7%)

Race
Population
Percentage (of total)
White7,56077.25%
Other race7117.26%
Two or more races4864.97%
Black or African American4124.21%
Asian3563.64%
Native American1972.01%
Native Hawaiian or Pacific Islander650.66%

Monmouth Marital Status

OverallMalesFemales0%10%20%30%40%50%60%70%80%90%100%

Married

Widowed

Divorced

Separated

Never Married

Economics and Income Statistics

Monmouth's average per capita income is $41,178. Household income levels show a median of $60,911. The poverty rate stands at 15.17%.

Families: A family includes the owner or renter of the home along with everyone related to them - whether through birth, marriage, or adoption. This includes relatives like spouses, children, parents, siblings, grandparents, and any other family members.
Households: A household includes all the people who occupy a housing unit (such as a house or apartment) as their usual place of residence.
Non Families: A nonfamily household is either someone living alone or when the owner/renter lives with people they aren't related to, like roommates.
Name
Median
Mean
Married Families$94,533-
Families$77,951$88,786
Households$60,911$81,697
Non Families$40,943$62,387

$41,178

Average Income

$60,911

Median Household Income

15.17%

Poverty Rate

Nearby Cities

Sources

  1. US Census State Population Estimates - Most recent state estimates from the Census Bureau's Population Estimates Program
  2. US Census County Population Estimates - Most recent county estimates from the Census Bureau's Population Estimates Program
  3. American Community Survey (2009 - 2013)
  4. Census QuickFacts
  5. Historical Populations of States and Counties (1790 - 1990)