Delaware Population By County in 2011

Updated on June 16, 2025.

Based on the US Census Vintage data estimates, in 2011, the population of Delaware was 907,590. Among all Delaware counties, New Castle had the highest population (542,031), followed by Sussex (200,398), and Kent (165,161).

Hover over or click on the counties in the map below to see the populations. The data can also be found in a table below. You can use the table to sort, filter, and explore the data further.

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

See this for other years:
Delaware Population By County in 2011
Delaware Population By County in 2011
Items per page:
0 of 0
County Population % of State Population
Kent 165161 18.20
New Castle 542031 59.72
Sussex 200398 22.08