Connecticut Citizen Population By County in 2018 (ACS-5Yrs)

Updated on March 28, 2026.

Based on the US Census Bureau's special tabulation from the ACS 5-year estimates, in 2018, the citizen population for Connecticut was 3,330,685 and represented 93.00% of the total Connecticut population.

Among all Connecticut counties, Fairfield had the highest citizen population (835.57K), followed by Hartford (833.70K), and New Haven (807.77K).

In terms of percentages, Windham had the highest percentage of its population being citizens (97.41%), followed by Middlesex (96.76%), and Tolland (96.73%).

The chart and table below shows the citizen population of each county and the percentage of each county's population that were citizens.

You can see similar information for other states and by state for the United States.

See this for other years:
Connecticut Citizen Population By County in 2018
Connecticut Citizen Population By County in 2018
Items per page:
0 of 0
County Citizen Population % of County Population
Fairfield 835570 88.48
Hartford 833700 93.18
New Haven 807765 94.00
New London 259190 96.40
Litchfield 176530 96.45
Middlesex 158075 96.76
Tolland 146330 96.73
Windham 113525 97.41