Fastest Growing Counties in Delaware (2026)

County
Rank
Change (2020)
2026 Pop.
2020 Pop.
Sussex County119.61%285,452238,654
Kent County28.51%197,824182,317
New Castle County35.02%599,629570,957

Delaware Counties Growth Overview

Delaware's counties show varied growth patterns from 2020 to 2026. Sussex County leads with 3.03% annualized growth, followed by Kent County (1.37%) and New Castle County (0.82%). The largest counties are New Castle County (599,629), Sussex County (285,452), and Kent County (197,824). All 3 counties in Delaware are growing. Overall, counties averaged 1.74% annualized growth, with total population growing by 1.47% annually.

Change (2020)

-0.05

-0.025

0

0.025

0.05

0.075