County outline
Where Grant County is located
Area breakdown
Land accounts for 98.9% of Grant County’s measured area and water for 1.1%. Its combined area converts to 675.4 square kilometers or approximately 166,895 acres.
Green: land · blue: water
| Measurement | Square miles | Square kilometers | Acres |
|---|---|---|---|
| Land | 257.976 | 668.155 | 165,104.6 |
| Water | 2.798 | 7.247 | 1,790.7 |
| Total | 260.774 | 675.402 | 166,895.4 |
How Grant County compares
By original Census land area, Grant County ranks #79 of 120 in Kentucky and #2890 of 3,222 nationally. National rankings include the 50 states, District of Columbia, and Puerto Rico.
Its land area is 0.843 times the Kentucky county-equivalent median of 306 square miles. It accounts for 0.7% of the combined county land area in the state.
See the complete Kentucky ranking · What counts as a county equivalent?
Population and density of Grant County
The Census Bureau estimates that 26,181 people lived in Grant County on July 1, 2025. That ranks #1,620 of 3,222 county equivalents nationally and #43 of 120 in Kentucky. Since the April 1, 2020 estimates base of 24,942, the population has grown by 1,239 (+5%), compared with +2.2% for Kentucky as a whole.
With 258 square miles of land, that is 101 people per square mile (39 per km²), placing Grant County #978 nationally for density and #30 in Kentucky. The median county equivalent has 47 people per square mile; the Kentucky median is 59. Put another way, there are about 6.3 acres of land per resident.
| July 1 | 2020 | 2021 | 2022 | 2023 | 2024 | 2025 |
|---|---|---|---|---|---|---|
| Estimate | 25,014 | 25,299 | 25,473 | 25,626 | 25,732 | 26,181 |
| Change | — | +285 | +174 | +153 | +106 | +449 |
U.S. Census Bureau, Vintage 2025 population estimates. Estimates are revised each year and are not decennial census counts. Density divides the whole population by the whole county’s land area, so it describes an average, not how settlement is distributed within the county. Population sources and methods.
Cities and towns in Grant County
4 incorporated places lie at least partly in Grant County. Together they are home to 10,700 people (40.9%); the other 15,481 (59.1%) live outside any incorporated place, in unincorporated communities and rural areas.
The largest is Crittenden city, with 4,185 residents in the county (the city extends into 1 other county). The county seat, Williamstown city, has 4,030 residents. By land, Williamstown city is the largest at 16.8 mi² across all its counties. Among places with at least 1,000 residents in 2020, Crittenden city grew fastest since then (+4.1%).
| Incorporated place | Population 2025 | Since 2020 | Land mi² |
|---|---|---|---|
| Crittenden cityAlso in 1 other county | 4,185 | +4.1% | 3.405 |
| Williamstown cityCounty seat · Also in 1 other county | 4,030 | +3.1% | 16.8 |
| Dry Ridge city | 2,249 | +3.7% | 5.162 |
| Corinth cityAlso in 1 other county | 236 | +3.5% | 2.118 |
Population: U.S. Census Bureau Vintage 2025 subcounty estimates, counting only the part of each place inside Grant County. Land: 2026 Census Gazetteer, for the whole place even where it extends into other counties. How communities are listed.
Metropolitan area
Grant County is an outlying county of the Cincinnati, OH-KY-IN Metropolitan Statistical Area. Its 15 county equivalents have 2,312,858 residents on 4,385.2 square miles of land; Grant County accounts for 5.9% of the land and 1.1% of the residents. By combined land it ranks #60 of 393 metropolitan areas, and #30 by population. It belongs to the Cincinnati-Wilmington, OH-KY-IN Combined Statistical Area.
| County equivalent | Population 2025 | Land mi² |
|---|---|---|
| Hamilton CountyOhio | 838,418 | 405.5 |
| Butler CountyOhio | 400,128 | 466.5 |
| Warren CountyOhio | 257,181 | 401.4 |
| Clermont CountyOhio | 216,977 | 452.6 |
| Kenton County | 175,779 | 160.4 |
| Boone County | 145,316 | 246.3 |
| Campbell County | 95,441 | 151.3 |
| Dearborn CountyIndiana | 51,609 | 305.1 |
| Brown CountyOhio | 44,397 | 489.6 |
| Grant County | 26,181 | 258 |
| Franklin CountyIndiana | 23,286 | 384.4 |
| Pendleton County | 14,800 | 277.1 |
| Gallatin County | 8,840 | 98.3 |
| Bracken County | 8,511 | 202.7 |
| Ohio CountyIndiana | 5,994 | 86.2 |
ZIP codes
8 ZIP Code Tabulation Areas have land in Grant County; 4 of them have most of their land inside the county, and the others mainly cover neighboring areas.
4100341010410304103541046410524109241097
ZIP Code Tabulation Areas are the Census Bureau’s approximations of USPS ZIP Code service areas, from the 2020 Census relationship files. Lighter codes have less than half of their land in this county. Post-office-box and single-address ZIP Codes have no tabulation area.
Counties bordering Grant County
Grant County shares a land border with 7 county equivalents. It has more land than 3 of them. The largest neighbor is Owen County (350.5 mi²) and the smallest is Gallatin County (98.3 mi²). Together with its neighbors, Grant County forms a block of 1,979.2 mi² of land, of which it holds 13%.
| Bordering county equivalent | Land mi² | Size vs. Grant | Compare |
|---|---|---|---|
| Owen County | 350.5 | 1.4× larger | Compare |
| Harrison County | 306.5 | 1.2× larger | Compare |
| Scott County | 282.2 | 1.1× larger | Compare |
| Pendleton County | 277.1 | 1.1× larger | Compare |
| Boone County | 246.3 | about the same | Compare |
| Kenton County | 160.4 | 1.6× smaller | Compare |
| Gallatin County | 98.3 | 2.6× smaller | Compare |
How big is Grant County compared with U.S. states?
Grant County has less land than any of the 50 states. Rhode Island, the smallest state by land area, has 1,033.9 mi², about 4 times as much. Kentucky’s county land could hold about 153 areas the size of Grant County.
Another way to picture it: the same land area would fill a square about 16.1 miles (25.8 km) on each side. Real county shapes are rarely square, so this is a scale reference rather than a width or driving distance.
State figures are the sums of each state’s county-equivalent land measurements in the same Census release, so states and counties are compared on the same basis. Published state totals can differ slightly because of rounding. Compare all states · Counties bigger than entire states.
What stands out about Grant County?
Grant County has more land than 332 of the other 3,221 county equivalents in the dataset.
A median is the middle county-equivalent measurement, not the average of the largest and smallest. All three bars use the same linear scale. Very small areas may appear as a thin sliver; the labels retain their values.
Does including water change its rank?
Using land plus water places Grant County at #2,923 nationally by total area, 33 places farther from the top than its land rank. Other county equivalents gain more area when their water measurements are included.
Its water share is 1.1%, compared with a national county-equivalent median of 1.2%. The two percentages are within 0.1 percentage points of each other. This describes the statistical geography’s land/water mix, not flood exposure or developable land.
Closest positions in the national land ranking
These entries sit immediately beside Grant County in the national ranking. They can be in different states and are not necessarily geographic neighbors.
| Land rank | County equivalent | Land mi² | Comparison |
|---|---|---|---|
| #2889 | Baldwin County, Georgia | 258.7 | Compare |
| #2890 | Grant County, Kentucky | 258 | This county |
| #2891 | McDuffie County, Georgia | 257.4 | Compare |
Calculated from the same Census release as the area table. Total-area order uses original ALAND + AWATER; water shares and chart labels use published square miles. Calculation details.
Representative coordinates
The Census internal point is 38.649167, -84.625924. It represents a location inside the geography; it is not necessarily the centroid or the address of a courthouse.
Source and precision
U.S. Census Bureau, 2026 Gazetteer Files, Counties. Original ALAND: 668,154,707 m²; AWATER: 7,246,424 m². Rankings use ALAND; exact ties use ascending GEOID. Tables preserve Census-published square miles to three decimals, with conversions based on those values.
Common questions
How big is Grant County?
Grant County, Kentucky has 258 square miles (668.2 km²) of land and 2.798 square miles of water, for a total area of 260.8 square miles. It ranks #2890 of 3,222 U.S. county equivalents by land area.
Is Grant County the largest county in Kentucky?
No. Grant County ranks #79 of 120 in Kentucky by land area. The largest is Pike County, with 786.2 square miles of land.
What counties border Grant County?
Grant County shares a land border with Owen County, Pendleton County, Gallatin County, Harrison County, Kenton County, Boone County, and Scott County.
What is the population of Grant County?
The Census Bureau estimates Grant County had 26,181 residents on July 1, 2025, ranking #1,620 of 3,222 county equivalents. That is 101 people per square mile of land.
What is the county seat of Grant County?
The county seat of Grant County is Williamstown.
What cities and towns are in Grant County?
Grant County has 4 incorporated places. The most populous are Crittenden city, Williamstown city, Dry Ridge city, and Corinth city; 15,481 residents live outside any incorporated place.
Is Grant County part of a metropolitan area?
Yes. It is an outlying county of the Cincinnati, OH-KY-IN Metropolitan Statistical Area, which has 15 county equivalents and 2,312,858 residents.
How many ZIP codes are in Grant County?
8 ZIP Code Tabulation Areas have land in Grant County, and 4 of them have most of their land inside the county. Census ZIP Code Tabulation Areas approximate USPS ZIP Code areas.
How does Grant County compare with U.S. states?
It has less land than every state. Rhode Island, the smallest, has 4 times as much land.
How many acres of land are in Grant County?
The land measurement converts to approximately 165,105 acres. Including water, total area is approximately 166,895 acres. One square mile equals 640 acres.
Why might another source show a different area?
Check whether it reports land or total area, its Census vintage, and its rounding. Our guide explains how to reconcile county area figures.
Can this establish a property boundary?
No. Statistical measurements and generalized maps do not establish property lines. Consult the relevant local surveying or land-records authority.