View source for Fairbury, Nebraska

===2020 census===
As of the [[2020 United States census|2020 census]], Fairbury had a population of 3,970.<ref name="Census2020PL">{{cite web|title=2020 Decennial Census Redistricting Data (Public Law 94-171)|url=https://api.census.gov/data/2020/dec/pl?get=NAME,P1_001N,P1_003N,P1_004N,P1_005N,P1_006N,P1_007N,P1_008N,P1_009N,P2_001N,P2_002N,H1_001N,H1_002N&for=place%3A16410&in=state%3A31|website=United States Census Bureau|year=2021|access-date=April 30, 2026|df=mdy}}</ref> The median age was 42.2 years. 24.0% of residents were under the age of 18 and 23.3% of residents were 65 years of age or older. For every 100 females there were 94.8 males, and for every 100 females age 18 and over there were 92.2 males age 18 and over.<ref name="Census2020DP">{{cite web|title=2020 Decennial Census Demographic Profile (DP1)|url=https://api.census.gov/data/2020/dec/dp?get=NAME,DP1_0021P,DP1_0024P,DP1_0025C,DP1_0049C,DP1_0045C,DP1_0069C,DP1_0073C,DP1_0125P,DP1_0126P,DP1_0129P,DP1_0133P,DP1_0137P,DP1_0138P,DP1_0139P,DP1_0141P,DP1_0142P,DP1_0143P,DP1_0145P,DP1_0146P,DP1_0147C,DP1_0148C,DP1_0149C,DP1_0156C,DP1_0157C,DP1_0158C,DP1_0159P,DP1_0160P&for=place%3A16410&in=state%3A31|website=United States Census Bureau|year=2021|access-date=April 30, 2026|df=mdy}}</ref>

99.6% of residents lived in urban areas, while 0.4% lived in rural areas.<ref name="Census2020DHC">{{cite web|title=2020 Decennial Census Demographic and Housing Characteristics (DHC)|url=https://api.census.gov/data/2020/dec/dhc?get=NAME,P2_002N,P2_003N&for=place%3A16410&in=state%3A31|website=United States Census Bureau|year=2023|access-date=April 30, 2026|df=mdy}}</ref>

There were 1,710 households in Fairbury, of which 24.7% had children under the age of 18 living in them. Of all households, 39.4% were married-couple households, 22.7% were households with a male householder and no spouse or partner present, and 30.1% were households with a female householder and no spouse or partner present. About 39.6% of all households were made up of individuals and 20.7% had someone living alone who was 65 years of age or older.<ref name="Census2020DP"/>

There were 2,005 housing units, of which 14.7% were vacant. The homeowner vacancy rate was 4.2% and the rental vacancy rate was 12.9%.<ref name="Census2020DP"/>

{| class="wikitable"
|+ Racial composition as of the 2020 census<ref name="Census2020PL"/>
! Race !! Number !! Percent
|-
| [[White Americans|White]] || 3,542 || 89.2%
|-
| [[African Americans|Black or African American]] || 16 || 0.4%
|-
| [[Native Americans in the United States|American Indian and Alaska Native]] || 42 || 1.1%
|-
| [[Asian Americans|Asian]] || 11 || 0.3%
|-
| [[Native Hawaiians|Native Hawaiian]] and [[Pacific Islander|Other Pacific Islander]] || 0 || 0.0%
|-
| Some other race || 147 || 3.7%
|-
| [[Multiracial Americans|Two or more races]] || 212 || 5.3%
|-
| ''[[Hispanic and Latino Americans|Hispanic or Latino]] (of any race)'' || 291 || 7.3%
|}