Ranking of Connecticut Counties By Population in 2020

Updated on June 18, 2025.

Based on the US Census Vintage data estimates, in 2020, the Population for Connecticut was 3.58M. Among all Connecticut counties, Capitol Planning Region had the highest population (964.09K), followed by Western Connecticut Planning Region (618.76K), and South Central Connecticut Planning Region (564.53K).

The chart below shows the top 9 counties, and the table below shows the ranking of all Connecticut counties.

You can see similar ranking information for related topics, and for other states. You can also see the ranking of all counties in the United States.

See this for other years:
Ranking of Connecticut Counties By Population in 2020
Capitol Planning Region
Western Connecticut Planning Region
South Central Connecticut Planning Region
Naugatuck Valley Planning Region
Greater Bridgeport Planning Region
Southeastern Connecticut Planning Region
Lower Connecticut River Valley Planning Region
Northwest Hills Planning Region
Northeastern Connecticut Planning Region
Ranking of Connecticut Counties By Population in 2020
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Rank County Population
1 Capitol Planning Region 964088
2 Western Connecticut Planning Region 618762
3 South Central Connecticut Planning Region 564526
4 Naugatuck Valley Planning Region 449055
5 Greater Bridgeport Planning Region 324397
6 Southeastern Connecticut Planning Region 278379
7 Lower Connecticut River Valley Planning Region 173281
8 Northwest Hills Planning Region 112199
9 Northeastern Connecticut Planning Region 95231