Population density (sq mi)2,19322891
Median age34.537.437.7
Male/Female ratio0.9:11.0:11.0:1
Married (15yrs & older)51%55%55%
Families w/ Kids under 1842%44%43%
Speak English83%77%79%
Speak Spanish13%13%13%

Key findings

  • The population density in Monmouth is 862% higher than Illinois
  • The median age in Monmouth is 8% lower than Illinois
  • In Monmouth 82.80% of the population is White
  • In Monmouth 4.67% of the population is Black
  • In Monmouth 3.65% of the population is Asian

Compare Monmouth, IL Demographics


      Monmouth population breakdown by race

      American Indian0.00%0.23%0.82%
      Native Hawaiian0.00%0.03%0.18%
      Mixed race2.51%2.34%3.06%
      Other race6.37%5.86%4.75%
      In Monmouth, 15.5% of people are of Hispanic or Latino origin.
      Please note: Hispanics may be of any race, so also are included in any/all of the applicable race categories above.

      Household income distribution

      Place of birth by citizenship

      Monmouth age breakdown

      Marital status

      Age of children in married couples

      Source: The Monmouth, IL demographics data displayed above is derived from the 2016 United States Census Bureau American Community Survey (ACS).