County Maps US

Montgomery County, Missouri

A county in Missouri, ranked 79 of 115 by population.

CountyFIPS 29139

Within Missouri
Montgomery County, highlighted, with the areas around it. Boundaries generalised from the 2025 Census cartographic boundary file; neighbour fills carry no data.

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Population
11,590
+297 (+2.6%) since 2020
Land area
535
square miles. A further 1.0% of the total area is water
Population density
21.7
people per square mile, computed rather than published
County seat
Montgomery City
Seat of county government.
Established
1818
207 years ago
Largest city
Montgomery City city
Population 2,782.

Sources: US Census Bureau, Population Estimates Program, Vintage 2025 Population Estimates, released 26 March 2026; US Census Bureau, Gazetteer Files, 2025 Gazetteer Files, released 10 September 2025; Wikidata (CC0), Wikidata. Retrieved 30 August 2026.

Satellite view

Aerial imagery of Montgomery County with its boundary drawn on top. A map shows you the shape; this shows you what is inside it, and which side of the line a place falls on.

Aerial view of Montgomery County, Missouri from the USGS National Map, with its boundary outlined
Imagery: USGS National Map, USGS Imagery Only, public domain, requested from USGS by your browser when you reach this point on the page, at 542 by 800 pixels. The boundary is the 2025 Census cartographic boundary file, reprojected to Web Mercator to match the imagery. You can also open the USGS National Map viewer.

Where Montgomery County ranks

Position among the 115 counties of Missouri, and among all 3,144 US counties and county-equivalents. Computed from the figures on this page.

MeasureValueIn MissouriNationally
Population11,59079th of 1152,311th of 3,144
Land area535 sq mi72nd of 1151,953rd of 3,144
Population density21.7 per sq mi78th of 1152,186th of 3,144
Median household income$65,50032nd of 1151,593rd of 3,143

Full data for Montgomery County

Every figure below is attributed to the Census Bureau product it came from, with the vintage of that product.
MeasureValueSource and vintage
Population11,590Vintage 2025 Population Estimates
Population in 202011,293Vintage 2025 Population Estimates
2020 estimates base?11,321Vintage 2025 Population Estimates
Land area535 sq mi2025 Gazetteer Files
Water area5.4 sq mi2025 Gazetteer Files
Total area540.5 sq mi2025 Gazetteer Files
Population density?21.7 per sq miComputed: Vintage 2025 estimates divided by 2025 Gazetteer land area
Median household income$65,500American Community Survey 2020-2024 5-Year Estimates
Median home value$178,700American Community Survey 2020-2024 5-Year Estimates
Median age43.6American Community Survey 2020-2024 5-Year Estimates
Households4,640American Community Survey 2020-2024 5-Year Estimates
Housing units5,832American Community Survey 2020-2024 5-Year Estimates

Sources: US Census Bureau, Population Estimates Program, Vintage 2025 Population Estimates, released 26 March 2026; US Census Bureau, Gazetteer Files, 2025 Gazetteer Files, released 10 September 2025; US Census Bureau, American Community Survey, American Community Survey 2020-2024 5-Year Estimates, released 29 January 2026. Population density is computed here, not published: it divides the Vintage 2025 population estimate by the 2025 Gazetteer land area, which are two different Census products. Retrieved 30 August 2026.

How the population changed

The Census Bureau publishes the components behind an estimate, not just the total. For the year to July 2025:

Births minus deaths
-46
112 births, 158 deaths
Net migration
+82
More people moved in than moved out.

Source: US Census Bureau, Population Estimates Program, Vintage 2025 Population Estimates, released 26 March 2026. Retrieved 30 August 2026.

The 7 areas bordering Montgomery County

Ordered by the length of the border actually shared, which the Census Bureau publishes in its county adjacency file and which no other county reference presents.

Bordering areaStateShared borderPopulation
Warren CountyMissouri28 mi39,016
Callaway CountyMissouri25 mi45,765
Audrain CountyMissouri18 mi24,528
Gasconade CountyMissouri15 mi14,784
Lincoln CountyMissouri10 mi66,676
Pike CountyMissouri8.0 mi17,955
Osage CountyMissouri0.4 mi13,611

Source: US Census Bureau, County Adjacency File, 2025 County Adjacency File, released 15 September 2025. Retrieved 30 August 2026.

All 115 counties of Missouri

Open the interactive Missouri county map, or jump straight to any of them.

Data on this page last rebuilt 30 August 2026. How these figures are produced.