Connecticut Population By County in 2021 (ACS-5Yrs)

Based on the US Census ACS-5Yrs estimates, in 2021, the total population of Connecticut was 3.61M. Among all Connecticut counties, Fairfield was the most populated county (956.45K), followed by Hartford (898.64K), and then New Haven (864.75K).

On the other hand, the least populated counties were: Windham (116.50K), Tolland (150.12K), and Middlesex (164.57K).

The chart and table below shows the population of each county and the percentage of Connecticut population in each county.

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