5th most populous of 67
With 584,882 residents in 2024, Delaware County ranks 5th by population among Pennsylvania's 67 counties and is home to 4.5% of the state's residents.

Delaware County has the 3rd youngest population in Pennsylvania (median age 39.1) and the 4th most expensive homes (median value $332,200).
Delaware County is home to 584,882 people (2024 estimate) on 184 square miles of land. This page brings together official U.S. Census Bureau population estimates since 2000, the components of change—births, deaths and migration—American Community Survey indicators on income, housing, poverty and education, BEA economic accounts and BLS unemployment.
Pick an indicator to see its long-run evolution.
U.S. Census Bureau: intercensal estimates 2000–2009, Vintage 2020 (2010–2019) and Vintage 2024 (2020–2024), July 1.
| Indicator | Value | Year and source |
|---|---|---|
| Population estimate | 584,882 | 2024 · U.S. Census Bureau |
| Population, 2010 Census | 558,979 | 2010 · U.S. Census Bureau |
| Population, 2000 | 551,536 | July 1, 2000 · Census intercensal |
| Change since 2000 | +6.0% | 2000–2024 · Census |
| International migration | +5,298 | 2024 · Census Vintage 2024 |
| Domestic migration | −2,034 | 2024 · Census Vintage 2024 |
| Birth rate | 10.9 per 1,000 | 2024 · calculated |
| Death rate | 9.1 per 1,000 | 2024 · calculated |
| Population rank in Pennsylvania | 5th of 67 | 2024 · calculated |
| Per capita personal income | $85,094 | BEA, 2024 · official |
| Gross domestic product | $42.6 billion | BEA, current dollars, 2024 · official |
| Median household income | $89,546 | ACS 2020–2024 5-year · official |
| Poverty rate | 10.2% | ACS 2020–2024 5-year · official |
| Bachelor’s degree or higher | 41.9% | Age 25+, ACS 2020–2024 5-year · official |
| Foreign-born residents | 11.2% | ACS 2020–2024 5-year · official |
| Median home value | $332,200 | ACS 2020–2024 5-year · official |
| Median gross rent | $1,372/month | ACS 2020–2024 5-year · official |
| Median age | 39.1 years | ACS 2020–2024 5-year · official |
| Households | 216,946 | ACS 2020–2024 5-year · official |
| Owner-occupied homes | 69.6% | ACS 2020–2024 5-year · official |
Comparable indicators for Delaware County, Pennsylvania and the United States.
| Indicator | County | Pennsylvania | U.S. | Reference |
|---|---|---|---|---|
| Population change 2020–2024 | +1.4% | +0.6% | +2.6% | Census Vintage 2024 |
| Birth rate (per 1,000) | 10.9 | 9.8 | 10.6 | 2024 |
| Death rate (per 1,000) | 9.1 | 10.5 | 9.1 | 2024 |
| Net migration rate (per 1,000) | 5.6 | 5.4 | 8.2 | 2024 |
| Population density (/mi²) | 3182.0 | 292.3 | 96.3 | 2024 |
| Per capita personal income | $85,094 | $70,678 | $73,204 | BEA, 2024 |
| Median household income | $89,546 | $77,971 | $80,734 | ACS 2020–2024 5-year |
| Poverty rate | 10.2% | 11.7% | 12.5% | ACS 2020–2024 5-year |
| Bachelor’s degree or higher | 41.9% | 35.2% | 35.7% | Age 25+, ACS 2020–2024 5-year |
| Foreign-born residents | 11.2% | 7.7% | 14.1% | ACS 2020–2024 5-year |
| Median home value | $332,200 | $254,500 | $332,700 | ACS 2020–2024 5-year |
| Median gross rent | $1,372/month | $1,209/month | $1,413/month | ACS 2020–2024 5-year |
| Median age | 39.1 years | 40.9 years | 38.9 years | ACS 2020–2024 5-year |
| Owner-occupied homes | 69.6% | 69.3% | 65.2% | ACS 2020–2024 5-year |
With 584,882 residents in 2024, Delaware County ranks 5th by population among Pennsylvania's 67 counties and is home to 4.5% of the state's residents.
Its population went from 551,536 in 2000 to 584,882 in 2024, a change of +6.0%, compared with +6.5% for Pennsylvania as a whole.
In the year to July 2024 the county recorded 6,376 births and 5,317 deaths, so births outnumbered deaths by 1,059.
Annual Census estimates since 2000 put the county's highest population in 2024, at 584,882.
Delaware County has about 3182.0 residents per square mile of land, ranking 2nd of 67 counties; Pennsylvania averages 292.3.
With a median household income of $89,546 (ACS 2020–2024 5-year), the county ranks 5th of 67 Pennsylvania counties; the state median is $77,971.
Its economy produced $42.6 billion of GDP in 2024 (BEA), 6th largest among 67 Pennsylvania counties.
Real GDP grew 0.6% in 2024, adjusted for inflation (BEA, chained 2017 dollars).