Connecticut Counties by Population (2026)
2026 Pop.
100K
200K
300K
400K
500K
600K
700K
800K
900K
Top 5 Most Populous Counties
999,036
465,218
| County | 2026 Pop. ↓ | Area (mi²) | Density (/mi²) | Change (2020) |
|---|---|---|---|---|
| Capitol Planning Region | 999,036 | 1K | 973 | 3.63% |
| Western Connecticut Planning Region | 643,243 | 532 | 1,209 | 3.96% |
| South Central Connecticut Planning Region | 579,944 | 367 | 1,580 | 2.75% |
| Naugatuck Valley Planning Region | 465,218 | 413 | 1,126 | 3.61% |
| Greater Bridgeport Planning Region | 339,003 | 140 | 2,421 | 4.51% |
| Southeastern Connecticut Planning Region | 284,859 | 598 | 476 | 2.33% |
| Lower Connecticut River Valley Planning Region | 177,575 | 424 | 419 | 2.49% |
| Northwest Hills Planning Region | 115,100 | 787 | 146 | 2.58% |
| Northeastern Connecticut Planning Region | 98,565 | 554 | 178 | 3.52% |
Sources
- US Census State Population Estimates - Most recent state estimates from the Census Bureau's Population Estimates Program
- US Census County Population Estimates - Most recent county estimates from the Census Bureau's Population Estimates Program
- American Community Survey (2009 - 2013)
- Census QuickFacts
- Historical Populations of States and Counties (1790 - 1990)