Town · Connecticut
Killingly, Connecticut
Killingly, town, in Northeastern Connecticut Planning Region, Connecticut. Killingly had 18,177 residents on July 1, 2025 by the Census Bureau's estimate, up 2.6% since 2020; the 2020 Census counted 17,752 and the ACS 2020-2024 5-year estimates put it at 17,867 (±21). GEOID 0915040500.
Residents, July 2025 estimate
18,177
Census Bureau estimate (no margin published)
2020 Census count: 17,752 · ACS 2020-2024: 17,867 ±21
Median household income
$84,350
±$8,277 (90% margin)
Connecticut: $95,781
Median home value
$288,600
±$15,229 (90% margin)
Connecticut: $366,900
Median gross rent
$1,044
±$141 (90% margin)
Connecticut: $1,488
Where is Killingly and what county is it in?
Killingly is a town in Northeastern Connecticut Planning Region, Connecticut. It covers 48.3 square miles of land, 367 residents per square mile in 2020.
2 places lie inside Killingly: Danielson (borough, 4,155 in 2020) and Dayville (CDP, 631 in 2020).
Killingly is in the Putnam, CT micropolitan statistical area (Census Bureau delineation, July 2023).
Source: 2024 Gazetteer and 2020 place-by-county files, U.S. Census Bureau · Census reference files
How many people live in Killingly, and is it growing?
The Census Bureau estimates that 18,177 people lived in Killingly on July 1, 2025, up 2.6% since 2020, in line with Connecticut (+2.2%). The 2020 Census counted 17,752 residents. The 2020-2024 American Community Survey, a five-year sample, puts the population at 17,867 (±21).
| Measure | Killingly | Northeastern Connecticut Planning Region | Change since 2015-2019 |
|---|---|---|---|
| Total population | 17,867±21 | 96,312 | – |
| Households | 7,300±277 | 39,412 | – |
| Average household size | 2.39±0.09 | 2.41 | – |
| Housing units | 7,678±282 | 41,736 | – |
Killingly's population since 2000
From 16,472 in 2000 to 18,177 in 2025: up 10.4%. The 2000, 2010 and 2020 figures are census counts, each for Killingly as it was drawn that year: a place that annexed land, or a community that has since incorporated, covered a different area then. The 2005 figure is the Census Bureau's intercensal estimate, revised to fit the 2000 and 2010 counts and drawn on 2010 boundaries; 2015 and 2025 are July 1 estimates made from the census before them.
Source: The 2000, 2010 and 2020 Census counts and the Census Bureau's population estimates (intercensal 2000-2010, Vintage 2020, Vintage 2025) · Census population estimates
Source: American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026); Census PEP Vintage 2025 (SUB-EST2025, CO-EST2025); 2020 Census P.L. 94-171 · Check it at data.census.gov
Who lives in Killingly?
The median resident of Killingly is 39.5 years old; 19.8% are under 18 and 19.7% are 65 or older. The largest group is non-Hispanic white residents at 85.6%, then Hispanic or Latino residents (of any race) at 5.4%. 5.1% of residents were born outside the United States.
| Measure | Killingly | Northeastern Connecticut Planning Region | Change since 2015-2019 |
|---|---|---|---|
| Median age | 39.5±3.0 | 44.1 | – |
| Under 18 years | 19.8%±2.1 pts | 18.4% | – |
| 65 years and over | 19.7%±2.5 pts | 19.8% | – |
| Male | 48.3%±2.3 pts | 50.0% | – |
| Hispanic or Latino (any race) | 5.4%±2.6 pts | 5.2% | – |
| White alone, not Hispanic | 85.6%±3.2 pts | 86.3% | – |
| Black or African American alone, not Hispanic | 2.6%±1.3 pts | 1.4% | – |
| Asian alone, not Hispanic | 0.8%±0.4 pts | 1.3% | – |
| American Indian and Alaska Native alone, not Hispanic | 0.0%±0.2 pts | 0.1% | – |
| Native Hawaiian and Other Pacific Islander alone, not Hispanic | 0.1%±0.1 pts | 0.1% | – |
| Two or more races, not Hispanic | 4.5%±1.5 pts | 5.1% | – |
| Some other race alone, not Hispanic | 0.9%±0.6 pts | 0.5% | – |
| Born outside the United States | 5.1%±2.6 pts | 4.4% | – |
| Speak a language other than English at home (age 5+) | 7.7%±3.3 pts | 6.3% | – |
| Civilian veterans (age 18+) | 6.9%±1.4 pts | 7.8% | – |
| With a disability | 13.6%±2.2 pts | 14.2% | – |
| No health insurance coverage | 5.6%±1.9 pts | 3.8% | – |
| High school graduate or higher (age 25+) | 90.2%±2.0 pts | 92.5% | – |
| Bachelor's degree or higher (age 25+) | 22.9%±3.0 pts | 26.1% | – |
| Graduate or professional degree (age 25+) | 8.8%±1.8 pts | 11.7% | – |
| Lived in the same house a year earlier | 86.9%±3.0 pts | 91.0% | – |
| Moved from another state in the past year | 3.1%±1.3 pts | 3.2% | – |
Source: American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026) (Data Profiles DP02, DP05) · Check it at data.census.gov
What do households in Killingly earn?
Half of Killingly's 7,300 households earn less than $84,350 a year (±$8,277), against $90,589 in Northeastern Connecticut Planning Region and $95,781 in Connecticut. 11.4% of residents live below the poverty line.
| Measure | Killingly | Northeastern Connecticut Planning Region | Change since 2015-2019 |
|---|---|---|---|
| Median household income | $84,350±$8,277 | $90,589 | – |
| Mean household income | $96,103±$5,735 | $113,121 | – |
| Per capita income | $40,277±$2,570 | $47,072 | – |
| People below the poverty line | 11.4%±3.5 pts | 7.5% | – |
| Children under 18 below the poverty line | 17.9%±9.6 pts | 10.1% | – |
| Households receiving SNAP | 16.6%±3.9 pts | 10.9% | – |
| Households with a computer | 96.3%±1.7 pts | 95.0% | – |
| Households with a broadband subscription | 93.9%±2.7 pts | 91.4% | – |
Source: American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026) (Data Profile DP03) · Check it at data.census.gov
What does housing cost in Killingly?
Owners occupy 71.6% of Killingly's occupied homes and renters 28.4%. The median owner-occupied home is valued at $288,600 by its owner (±$15,229). The median renter pays $1,044 a month including utilities, and 26.2% of renters pay 35% or more of their income on rent.
| Measure | Killingly | Northeastern Connecticut Planning Region | Change since 2015-2019 |
|---|---|---|---|
| Median home value (owner-occupied) | $288,600±$15,229 | $307,600 | – |
| Median gross rent | $1,044±$141 | $1,155 | – |
| Renters paying 35% or more of income on rent | 26.2%±9.1 pts | 30.0% | – |
| Median monthly owner costs, with a mortgage | $1,810±$89 | $1,985 | – |
| Owner-occupied homes | 71.6%±4.3 pts | 77.3% | – |
| Renter-occupied homes | 28.4%±4.3 pts | 22.7% | – |
| Housing units | 7,678±282 | 41,736 | – |
| Homeowner vacancy rate | 0.0%±0.8 pts | 0.3% | – |
| Rental vacancy rate | 0.7%±1.1 pts | 1.3% | – |
| Single-family detached homes | 66.2%±4.6 pts | 74.3% | – |
| Mobile homes | 1.9%±0.9 pts | 1.7% | – |
| Built 2020 or later | 0.8%±0.6 pts | 0.7% | – |
| Built 2010 to 2019 | 5.1%±1.7 pts | 3.8% | – |
| Built 1939 or earlier | 22.5%±4.4 pts | 22.9% | – |
| Households with no vehicle | 5.6%±2.1 pts | 4.8% | – |
Source: American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026) (Data Profile DP04) · Check it at data.census.gov
How many new homes is Killingly building?
Builders took permits for 29 new housing units in Killingly in 2025 (29 in single-family houses), 1.6 per 1,000 residents against 2.0 across Connecticut.
Counts of units in permits a local office issued; not every permitted unit is built. A year marked with months was reported for part of the year.
Source: Building Permits Survey, annual place files 2019-2025, U.S. Census Bureau · Census Building Permits Survey
How do people in Killingly work and get to work?
81.5% of Killingly's workers drive alone and 11.1% work from home. The average trip to work takes 27.9 minutes. The unemployment rate in 2020-2024 averaged 10.3%.
| Measure | Killingly | Northeastern Connecticut Planning Region | Change since 2015-2019 |
|---|---|---|---|
| In the labor force (age 16+) | 67.0%±3.4 pts | 65.8% | – |
| Unemployment rate | 10.3%±2.7 pts | 6.0% | – |
| Drove alone to work | 81.5%±3.4 pts | 79.8% | – |
| Carpooled | 5.1%±2.0 pts | 6.0% | – |
| Public transportation | 0.4%±0.5 pts | 0.3% | – |
| Walked | 0.8%±0.6 pts | 0.8% | – |
| Worked from home | 11.1%±2.3 pts | 11.9% | – |
| Mean travel time to work | 27.9 min±2.2 | 29.0 min | – |
Source: American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026) (Data Profile DP03) · Check it at data.census.gov
What census tracts are in Killingly?
4 census tracts lie mostly in Killingly (2020 census blocks). Their median household incomes run from $73,534 (Tract 9045) to $106,806 (Tract 9041.02).
| Tract | Residents, 2020-2024 | Median household income |
|---|---|---|
| Tract 9045Northeastern Connecticut Planning Region | 6,125 | $73,534 |
| Tract 9041.01Northeastern Connecticut Planning Region | 4,657 | $96,250 |
| Tract 9044Northeastern Connecticut Planning Region | 4,491 | $79,505 |
| Tract 9041.02Northeastern Connecticut Planning Region | 2,594 | $106,806 |
Source: American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026); 2020 block assignment files (tract share = share of the tract's census blocks in Killingly) · Census block assignment files
How does Killingly compare with other places in Connecticut?
By the Census Bureau's July 2025 estimates, Killingly is the 665th-most populous of the 16,079 U.S. towns and townships that have one and the 42nd-most populous of 142 in Connecticut.
Killingly ranks 230th of 294 places in Connecticut with 1,000 or more residents and a reliable estimate, by median household income.
| Measure | Rank | Of |
|---|---|---|
| Population, July 2025 estimate | 42nd | 142 |
| Growth 2020-2025 (PEP) | 63rd | 167 |
| Residents per square mile | 222nd | 303 |
| Median household income | 230th | 294 |
| Per capita income | 258th | 303 |
| Median home value | 231st | 300 |
| Median gross rent | 255th | 266 |
| Poverty rate | 45th | 202 |
| Bachelor's degree or higher | 271st | 297 |
| Median age | 248th | 301 |
| Owner-occupied share | 204th | 300 |
| Work from home | 225th | 279 |
| Travel time to work | 142nd | 302 |
Killingly's figures with every place in Connecticut (CSV)
Every place in Connecticut, sortable · Compare Killingly with other places
Source: PlainCities ranks computed from the American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026) and PEP Vintage 2025 · How ranks are computed
How reliable are the figures for Killingly?
8 of the 57 figures for Killingly on this page carry a coefficient of variation over 40% and are marked with a ring: they come from a small sample, so read them as rough.
The American Community Survey samples about one household in eight over five years, so every figure is an estimate with a 90% margin of error (shown under each value). A ring marks an estimate whose coefficient of variation is over 40%. A change is called only when the gap between the two periods is larger than their combined 90% margin (the square root of the sum of the two squared margins), the Census Bureau's test. How to read a margin of error.
Source: American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026): margins of error as published · ACS technical documentation
How these figures are made: methodology and release checks · reading a margin of error · every state · corrections
Not on this page: crime, weather and schools for Killingly are other agencies' records. Crime: the FBI's Crime Data Explorer · climate: NOAA's U.S. Climate Normals · schools: the National Center for Education Statistics' school search.