Arnold, MO Demographics
Arnold, MO is the 36th most populous of 1082 cities in Missouri, with 20,858 residents across 12 square miles. That is about 1,810 people per square mile.
At the 2020 census
| Population | 20,858 |
|---|---|
| Land area | 12 sq mi |
| Density | 1,810 / sq mi |
Data: 2020 Decennial Census · land area from Census TIGER/Line
How Arnold, MO compares to the US
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About this page
City statistics cover the municipal boundary only, not the wider metro area.
Figures come from the 2020 census and the American Community Survey, compared against national averages.