Connecticut Counties by Population (2026)
2026 Pop.
100K
200K
300K
400K
500K
600K
700K
800K
900K
1M
Top 5 Most Populous Counties
1,007,872
471,442
| County | 2026 Pop. ↓ | Area (mi²) | Density (/mi²) | Change (2020) |
|---|---|---|---|---|
| Capitol Planning Region | 1,007,872 | 1K | 981 | 4.54% |
| Western Connecticut Planning Region | 650,637 | 532 | 1,223 | 5.15% |
| South Central Connecticut Planning Region | 584,316 | 367 | 1,592 | 3.51% |
| Naugatuck Valley Planning Region | 471,442 | 413 | 1,142 | 4.99% |
| Greater Bridgeport Planning Region | 344,398 | 140 | 2,460 | 6.17% |
| Southeastern Connecticut Planning Region | 286,562 | 598 | 479 | 2.94% |
| Lower Connecticut River Valley Planning Region | 179,272 | 424 | 423 | 3.46% |
| Northwest Hills Planning Region | 115,227 | 787 | 146 | 2.7% |
| Northeastern Connecticut Planning Region | 99,435 | 554 | 179 | 4.41% |
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)