Winfield, Kansas

===2020 census===
The [[2020 United States census|2020 United States census]]<ref>{{Cite web |title=Explore Census Data |url=https://data.census.gov| access-date=2023-12-15 |website=data.census.gov}}</ref> counted 11,777 people, 4,339 households, and 2,687 families in Winfield. The population density was 1,057.2 per square mile (408.1/km{{sup|2}}). There were 5,136 housing units at an average density of 461.0 per square mile (178.0/km{{sup|2}}). The racial makeup was 80.28% (9,454) [[White (U.S. Census)|white]], 4.14% (487) [[African American (U.S. Census)|black or African-American]], 1.55% (182) [[Native American (U.S. Census)|Native American]], 3.49% (411) [[Asian (U.S. Census)|Asian]], 0.66% (78) [[Pacific Islander (U.S. Census)|Pacific Islander]], 2.42% (285) from [[Race (United States Census)|other races]], and 7.47% (880) from two or more races. [[Hispanic (U.S. Census)|Hispanic]] or [[Latino (U.S. Census)|Latino]] of any race was 9.0% (1,083) of the population.

Of the 4,339 households, 30.4% had children under the age of 18; 45.1% were married couples living together; 27.1% had a female householder with no husband present. 30.4% of households consisted of individuals and 14.6% had someone living alone who was 65 years of age or older. The average household size was 2.4 and the average family size was 3.1.

23.7% of the population was under the age of 18, 13.2% from 18 to 24, 24.5% from 25 to 44, 21.6% from 45 to 64, and 18.8% who were 65 years of age or older. The median age was 35.0 years. For every 100 females, the population had 106.7 males. For every 100 females ages 18 and older, there were 109.8 males.

The 2016-2020 5-year [[American Community Survey|American Community Survey]]<ref>{{Cite web |title=Explore Census Data |url=https://data.census.gov|access-date=2023-12-15|website=data.census.gov}}</ref> estimates show that the median household income was $48,027 (with a margin of error of +/- $3,412) and the median family income $57,236 (+/- $5,345). Males had a median income of $31,570 (+/- $3,388) versus $25,677 (+/- $2,934) for females. The median income for those above 16 years old was $28,904 (+/- $3,107). Approximately, 12.5% of families and 18.7% of the population were below the [[poverty line]], including 24.2% of those under the age of 18 and 12.7% of those ages 65 or over.