City · Kansas
St. Marys, Kansas
St. Marys, city, in Pottawatomie County, Kansas. St. Marys had 2,790 residents on July 1, 2025 by the Census Bureau's estimate, up 0.9% since 2020; the 2020 Census counted 2,759 and the ACS 2020-2024 5-year estimates put it at 2,788 (±286). GEOID 2062400.
Residents, July 2025 estimate
2,790
Census Bureau estimate (no margin published)
2020 Census count: 2,759 · ACS 2020-2024: 2,788 ±286
Median household income
$76,771
±$12,333 (90% margin)
Kansas: $74,275
Median home value
$206,900
±$18,967 (90% margin)
Kansas: $217,200
Median gross rent
$892
±$123 (90% margin)
Kansas: $1,060
Where is St. Marys and what county is it in?
St. Marys is a city in Pottawatomie County, Kansas. It covers 1.2 square miles of land, 2,342 residents per square mile in 2020.
St. Marys is in the Manhattan, KS metropolitan statistical area, which takes in 3 counties (Census Bureau delineation, July 2023).
St. Marys lies mostly within St. Marys Township, a township with its own local government (2020 census blocks).
| County | 2020 residents | Share |
|---|---|---|
| Pottawatomie County | 2,759 | 100.0% |
| Wabaunsee County | land only, no residents | – |
Source: 2024 Gazetteer and 2020 place-by-county files, U.S. Census Bureau · Census reference files
How many people live in St. Marys, and is it growing?
The Census Bureau estimates that 2,790 people lived in St. Marys on July 1, 2025, up 0.9% since 2020, in line with Kansas (+1.3%). The 2020 Census counted 2,759 residents. The 2020-2024 American Community Survey, a five-year sample, puts the population at 2,788 (±286).
| Measure | St. Marys | Pottawatomie County | Change since 2015-2019 |
|---|---|---|---|
| Total population | 2,788 ±286 | 26,204 | no clear change |
| Households | 905 ±133 | 9,381 | no clear change |
| Average household size | 3.01 ±0.38 | 2.75 | no clear change |
| Housing units | 965 ±136 | 10,214 | no clear change |
St. Marys's population since 2000
From 2,198 in 2000 to 2,790 in 2025: up 26.9%. The 2000, 2010 and 2020 figures are census counts, each for St. Marys as it was drawn that year: a place that annexed land, or a community that has since incorporated, covered a different area then. The 2005 figure is the Census Bureau's intercensal estimate, revised to fit the 2000 and 2010 counts and drawn on 2010 boundaries; 2015 and 2025 are July 1 estimates made from the census before them.
Source: The 2000, 2010 and 2020 Census counts and the Census Bureau's population estimates (intercensal 2000-2010, Vintage 2020, Vintage 2025) · Census population estimates
Source: American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026); Census PEP Vintage 2025 (SUB-EST2025, CO-EST2025); 2020 Census P.L. 94-171 · Check it at data.census.gov
Who lives in St. Marys?
The median resident of St. Marys is 26.6 years old; 25.0% are under 18 and 12.3% are 65 or older. The largest group is non-Hispanic white residents at 79.2%, then Hispanic or Latino residents (of any race) at 9.6%. 4.2% of residents were born outside the United States.
| Measure | St. Marys | Pottawatomie County | Change since 2015-2019 |
|---|---|---|---|
| Median age | 26.6 ±4.1 | 36.4 | no clear change |
| Under 18 years | 25.0% ±5.4 pts | 28.8% | – |
| 65 years and over | 12.3% ±2.8 pts | 15.3% | – |
| Male | 52.7% ±3.9 pts | 50.2% | – |
| Hispanic or Latino (any race) | 9.6% ±5.0 pts | 6.1% | no clear change |
| White alone, not Hispanic | 79.2% ±7.6 pts | 87.1% | no clear change |
| Black or African American alone, not Hispanic | 0.5% ±0.8 pts | 1.6% | – |
| Asian alone, not Hispanic | 2.4% ±2.2 pts | 0.4% | – |
| American Indian and Alaska Native alone, not Hispanic | 0.1% ±0.2 pts | 0.2% | – |
| Native Hawaiian and Other Pacific Islander alone, not Hispanic | 0.0% ±1.1 pts | 0.1% | – |
| Two or more races, not Hispanic | 4.4% ±2.2 pts | 3.7% | – |
| Some other race alone, not Hispanic | 3.7% ±4.9 pts | 0.7% | – |
| Born outside the United States | 4.2% ±2.3 pts | 2.3% | no clear change |
| Speak a language other than English at home (age 5+) | 5.9% ±2.8 pts | 2.9% | – |
| Civilian veterans (age 18+) | 8.5% ±3.2 pts | 10.2% | – |
| With a disability | 10.2% ±3.6 pts | 11.2% | – |
| No health insurance coverage | 8.0% ±4.0 pts | 4.7% | – |
| High school graduate or higher (age 25+) | 96.3% ±2.4 pts | 96.4% | – |
| Bachelor's degree or higher (age 25+) | 24.7% ±5.3 pts | 38.2% | no clear change |
| Graduate or professional degree (age 25+) | 4.7% ±2.4 pts | 13.9% | – |
| Lived in the same house a year earlier | 85.7% ±5.0 pts | 91.5% | – |
| Moved from another state in the past year | 2.0% ±1.2 pts | 1.2% | – |
Source: American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026) (Data Profiles DP02, DP05) · Check it at data.census.gov
What do households in St. Marys earn?
Half of St. Marys's 905 households earn less than $76,771 a year (±$12,333), against $92,325 in Pottawatomie County and $74,275 in Kansas. In 2015-2019 it was $74,649 in 2024 dollars; the margins of error cannot tell the two periods apart. 8.6% of residents live below the poverty line.
| Measure | St. Marys | Pottawatomie County | Change since 2015-2019 |
|---|---|---|---|
| Median household income | $76,771 ±$12,333 | $92,325 | no clear change |
| Mean household income | $85,366 ±$8,425 | $105,915 | – |
| Per capita income | $28,921 ±$3,753 | $38,494 | no clear change |
| People below the poverty line | 8.6% ±4.5 pts | 6.7% | no clear change |
| Children under 18 below the poverty line | 11.9% ±10.1 pts | 6.5% | – |
| Households receiving SNAP | 5.6% ±3.2 pts | 4.4% | – |
| Households with a computer | 93.8% ±3.8 pts | 96.1% | – |
| Households with a broadband subscription | 93.7% ±3.7 pts | 92.5% | – |
Source: American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026) (Data Profile DP03) · Check it at data.census.gov
What does housing cost in St. Marys?
Owners occupy 64.3% of St. Marys's occupied homes and renters 35.7%. The median owner-occupied home is valued at $206,900 by its owner (±$18,967). The median renter pays $892 a month including utilities.
| Measure | St. Marys | Pottawatomie County | Change since 2015-2019 |
|---|---|---|---|
| Median home value (owner-occupied) | $206,900 ±$18,967 | $245,900 | no clear change |
| Median gross rent | $892 ±$123 | $924 | no clear change |
| Renters paying 35% or more of income on rent | 19.5% ±13.0 pts | 29.0% | – |
| Median monthly owner costs, with a mortgage | $1,464 ±$211 | $1,814 | – |
| Owner-occupied homes | 64.3% ±7.1 pts | 82.2% | −12.4 pts |
| Renter-occupied homes | 35.7% ±7.1 pts | 17.8% | – |
| Housing units | 965 ±136 | 10,214 | no clear change |
| Homeowner vacancy rate | 0.0% ±5.0 pts | 0.1% | – |
| Rental vacancy rate | 0.0% ±8.9 pts | 6.4% | – |
| Single-family detached homes | 80.2% ±7.6 pts | 79.4% | – |
| Mobile homes | 0.4% ±0.6 pts | 10.1% | – |
| Built 2020 or later | 0.3% ±0.5 pts | 2.8% | – |
| Built 2010 to 2019 | 6.1% ±4.2 pts | 17.6% | – |
| Built 1939 or earlier | 32.8% ±6.5 pts | 17.7% | – |
| Households with no vehicle | 3.0% ±2.6 pts | 1.7% | – |
Source: American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026) (Data Profile DP04) · Check it at data.census.gov
How many new homes is St. Marys building?
Builders took permits for 3 new housing units in St. Marys in 2025 (3 in single-family houses), 1.1 per 1,000 residents against 3.5 across Kansas.
Counts of units in permits a local office issued; not every permitted unit is built. A year marked with months was reported for part of the year.
Source: Building Permits Survey, annual place files 2019-2025, U.S. Census Bureau · Census Building Permits Survey
How do people in St. Marys work and get to work?
72.2% of St. Marys's workers drive alone and 5.7% work from home. The average trip to work takes 15.8 minutes. The unemployment rate in 2020-2024 averaged 4.4%.
| Measure | St. Marys | Pottawatomie County | Change since 2015-2019 |
|---|---|---|---|
| In the labor force (age 16+) | 66.4% ±5.8 pts | 65.5% | – |
| Unemployment rate | 4.4% ±2.8 pts | 2.1% | – |
| Drove alone to work | 72.2% ±5.8 pts | 80.2% | – |
| Carpooled | 11.3% ±4.4 pts | 9.4% | – |
| Public transportation | 0.0% ±2.2 pts | 0.0% | – |
| Walked | 10.0% ±4.4 pts | 2.3% | – |
| Worked from home | 5.7% ±3.3 pts | 7.4% | – |
| Mean travel time to work | 15.8 min ±1.9 | 23.2 min | no clear change |
Source: American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026) (Data Profile DP03) · Check it at data.census.gov
What census tracts are in St. Marys?
No census tract lies mostly in St. Marys; 2 tracts reach into it (2020 census blocks).
| Tract | Residents, 2020-2024 | Median household income |
|---|---|---|
| Tract 3Pottawatomie County | 5,124 | $74,379 |
| Tract 4831Wabaunsee County | 4,660 | $76,957 |
Source: American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026); 2020 block assignment files (tract share = share of the tract's census blocks in St. Marys) · Census block assignment files
How does St. Marys compare with other places in Kansas?
By the Census Bureau's July 2025 estimates, St. Marys is the 6,571st-most populous of the 19,476 U.S. incorporated places that have one and the 92nd-most populous of 625 in Kansas.
St. Marys ranks 145th of 374 places in Kansas with 1,000 or more residents and a reliable estimate, by median household income.
| Measure | Rank | Of |
|---|---|---|
| Population, July 2025 estimate | 92nd | 625 |
| Growth 2020-2025 (PEP) | 126th | 373 |
| Residents per square mile | 15th | 376 |
| Median household income | 145th | 374 |
| Per capita income | 318th | 375 |
| Median home value | 129th | 370 |
| Median gross rent | 155th | 333 |
| Poverty rate | 159th | 266 |
| Bachelor's degree or higher | 218th | 374 |
| Median age | 363rd | 376 |
| Owner-occupied share | 313th | 374 |
| Work from home | 187th | 233 |
| Travel time to work | 292nd | 375 |
St. Marys's figures with every place in Kansas (CSV)
Every place in Kansas, sortable · Compare St. Marys with other places
Source: PlainCities ranks computed from the American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026) and PEP Vintage 2025 · How ranks are computed
How reliable are the figures for St. Marys?
14 of the 57 figures for St. Marys on this page carry a coefficient of variation over 40% and are marked with a ring: they come from a small sample, so read them as rough.
The American Community Survey samples about one household in eight over five years, so every figure is an estimate with a 90% margin of error (shown under each value). A ring marks an estimate whose coefficient of variation is over 40%. A change is called only when the gap between the two periods is larger than their combined 90% margin (the square root of the sum of the two squared margins), the Census Bureau's test. How to read a margin of error.
Source: American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026): margins of error as published · ACS technical documentation
How these figures are made: methodology and release checks · reading a margin of error · every state · corrections
Not on this page: crime, weather and schools for St. Marys are other agencies' records. Crime: the FBI's Crime Data Explorer · climate: NOAA's U.S. Climate Normals · schools: the National Center for Education Statistics' public schools in St. Marys.