Connecticut Counties by Population (2026)

2026 Pop.

100K

200K

300K

400K

500K

600K

700K

800K

900K

1M

Top 5 Most Populous Counties

9 Counties

County
2026 Pop.
Area (mi²)
Density
Change (2020)
Capitol Planning Region1,007,8721K9814.54%
Western CT Planning Region650,6375321,2235.15%
South Central CT Planning Region584,3163671,5923.51%
Naugatuck Valley Planning Region471,4424131,1424.99%
Greater Bridgeport Planning Region344,3981402,4606.17%
Southeastern CT Planning Region286,5625984792.94%
Lower CT River Valley Planning Region179,2724244233.46%
Northwest Hills Planning Region115,2277871462.7%
Northeastern CT Planning Region99,4355541794.41%

Overview of Connecticut Counties

Sources

  1. US Census State Population Estimates - Most recent state estimates from the Census Bureau's Population Estimates Program
  2. US Census County Population Estimates - Most recent county estimates from the Census Bureau's Population Estimates Program
  3. American Community Survey (2009 - 2013)
  4. Census QuickFacts
  5. Historical Populations of States and Counties (1790 - 1990)