Ottawa, Illinois

==Demographics==
{{US Census population
|1870= 7736
|1880= 7834
|1890= 9985
|1900= 10588
|1910= 9535
|1920= 10816
|1930= 15094
|1940= 16005
|1950= 16957
|1960= 19408
|1970= 18716
|1980= 18166
|1990= 17451
|2000= 18307
|2010= 18768
|2020= 18840
|footnote=U.S. Decennial Census<ref name="DecennialCensus">{{cite web|url=https://www.census.gov/programs-surveys/decennial-census.html|title=Census of Population and Housing|publisher=Census.gov|access-date=June 4, 2015}}</ref>
}}As of the [[2020 United States census|2020 census]]<ref>{{Cite web |title=Explore Census Data |url=https://data.census.gov/cedsci/profile?g=1600000US1756926 |access-date=2022-06-28 |website=data.census.gov}}</ref> there were 18,840 people, 7,764 households, and 4,658 families residing in the city. The population density was {{Convert|1,214.23|PD/sqmi|PD/km2}}. There were 9,014 housing units at an average density of {{Convert|580.95|/sqmi|/km2}}. The racial makeup of the city was 86.36% [[White (U.S. Census)|White]], 2.45% [[African American (U.S. Census)|African American]], 0.44% [[Native American (U.S. Census)|Native American]], 1.04% [[Asian (U.S. Census)|Asian]], 0.04% [[Pacific Islander (U.S. Census)|Pacific Islander]], 2.55% from [[Race (United States Census)|other races]], and 7.13% from two or more races. [[Hispanic (U.S. Census)|Hispanic]] or [[Latino (U.S. Census)|Latino]] of any race were 9.50% of the population.

There were 7,764 households, out of which 31.1% had children under the age of 18 living with them, 39.70% were married couples living together, 15.38% had a female householder with no husband present, and 40.01% were non-families. 34.31% of all households were made up of individuals, and 14.95% had someone living alone who was 65 years of age or older. The average household size was 2.93 and the average family size was 2.36.

The city's age distribution consisted of 24.1% under the age of 18, 8.6% from 18 to 24, 22.9% from 25 to 44, 27.3% from 45 to 64, and 17.1% who were 65 years of age or older. The median age was 39.5 years. For every 100 females, there were 87.2 males. For every 100 females age 18 and over, there were 86.1 males.

The median income for a household in the city was $53,544, and the median income for a family was $64,128. Males had a median income of $39,677 versus $26,514 for females. The [[per capita income]] for the city was $28,365. About 13.5% of families and 16.8% of the population were below the [[poverty line]], including 24.9% of those under age 18 and 6.5% of those age 65 or over.