County outline
Where Marlboro County is located
Area breakdown
Land accounts for 98.8% of Marlboro County’s measured area and water for 1.2%. Its combined area converts to 1,257.4 square kilometers or approximately 310,700 acres.
Green: land · blue: water
| Measurement | Square miles | Square kilometers | Acres |
|---|---|---|---|
| Land | 479.874 | 1,242.868 | 307,119.4 |
| Water | 5.594 | 14.488 | 3,580.2 |
| Total | 485.468 | 1,257.356 | 310,699.5 |
How Marlboro County compares
By original Census land area, Marlboro County ranks #37 of 46 in South Carolina and #2156 of 3,222 nationally. National rankings include the 50 states, District of Columbia, and Puerto Rico.
Its land area is 0.778 times the South Carolina county-equivalent median of 616.9 square miles. It accounts for 1.6% of the combined county land area in the state.
See the complete South Carolina ranking · What counts as a county equivalent?
Population and density of Marlboro County
The Census Bureau estimates that 25,488 people lived in Marlboro County on July 1, 2025. That ranks #1,653 of 3,222 county equivalents nationally and #36 of 46 in South Carolina. Since the April 1, 2020 estimates base of 26,667, the population has declined by 1,179 (−4.4%), compared with +8.8% for South Carolina as a whole.
With 479.9 square miles of land, that is 53 people per square mile (21 per km²), placing Marlboro County #1,492 nationally for density and #32 in South Carolina. The median county equivalent has 47 people per square mile; the South Carolina median is 78. Put another way, there are about 12 acres of land per resident.
| July 1 | 2020 | 2021 | 2022 | 2023 | 2024 | 2025 |
|---|---|---|---|---|---|---|
| Estimate | 26,494 | 26,077 | 25,952 | 25,745 | 25,544 | 25,488 |
| Change | — | −417 | −125 | −207 | −201 | −56 |
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 Marlboro County
5 incorporated places lie at least partly in Marlboro County. Together they are home to 10,293 people (40.4%); the other 15,195 (59.6%) live outside any incorporated place, in unincorporated communities and rural areas.
The largest is Bennettsville city, with 7,565 residents in the county.
| Incorporated place | Population 2025 | Since 2020 | Land mi² |
|---|---|---|---|
| Bennettsville cityCounty seat | 7,565 | −6.5% | 6.34 |
| McColl town | 1,974 | −4.5% | 0.955 |
| Clio town | 577 | −4.6% | 0.822 |
| Blenheim town | 107 | −5.3% | 0.602 |
| Tatum town | 70 | −5.4% | 0.85 |
Population: U.S. Census Bureau Vintage 2025 subcounty estimates, counting only the part of each place inside Marlboro County. Land: 2026 Census Gazetteer, for the whole place even where it extends into other counties. How communities are listed.
Metropolitan area
Marlboro County is not part of any metropolitan or micropolitan statistical area in the Office of Management and Budget’s July 2023 delineation; 1,306 other county equivalents are also outside one. These areas are built around an urban core of at least 10,000 people plus the counties tied to it by commuting, so counties outside them are generally rural.
ZIP codes
8 ZIP Code Tabulation Areas have land in Marlboro County; 6 of them have most of their land inside the county, and the others mainly cover neighboring areas.
2951229516295202952529565295702959429596
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 Marlboro County
Marlboro County shares a land border with 7 county equivalents, including 3 in North Carolina. It has more land than 3 of them. The largest neighbor is Robeson County (947.3 mi²) and the smallest is Scotland County (319.1 mi²). Together with its neighbors, Marlboro County forms a block of 4,785.2 mi² of land, of which it holds 10%.
| Bordering county equivalent | Land mi² | Size vs. Marlboro | Compare |
|---|---|---|---|
| Robeson CountyNorth Carolina | 947.3 | 2× larger | Compare |
| Florence County | 800.5 | 1.7× larger | Compare |
| Chesterfield County | 799 | 1.7× larger | Compare |
| Darlington County | 560.6 | 1.2× larger | Compare |
| Richmond CountyNorth Carolina | 473.7 | about the same | Compare |
| Dillon County | 405.1 | 1.2× smaller | Compare |
| Scotland CountyNorth Carolina | 319.1 | 1.5× smaller | Compare |
How big is Marlboro County compared with U.S. states?
Marlboro County has less land than any of the 50 states. Rhode Island, the smallest state by land area, has 1,033.9 mi², about 2.2 times as much. South Carolina’s county land could hold about 63 areas the size of Marlboro County.
Another way to picture it: the same land area would fill a square about 21.9 miles (35.3 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 Marlboro County?
Marlboro County has more land than 1,066 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 Marlboro County at #2,228 nationally by total area, 72 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 1.2%, 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 Marlboro County in the national ranking. They can be in different states and are not necessarily geographic neighbors.
| Land rank | County equivalent | Land mi² | Comparison |
|---|---|---|---|
| #2155 | Campbell County, Tennessee | 480.2 | Compare |
| #2156 | Marlboro County, South Carolina | 479.9 | This county |
| #2157 | Macomb County, Michigan | 479.4 | 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 34.601670, -79.679435. 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: 1,242,867,256 m²; AWATER: 14,489,018 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 Marlboro County?
Marlboro County, South Carolina has 479.9 square miles (1,242.9 km²) of land and 5.594 square miles of water, for a total area of 485.5 square miles. It ranks #2156 of 3,222 U.S. county equivalents by land area.
Is Marlboro County the largest county in South Carolina?
No. Marlboro County ranks #37 of 46 in South Carolina by land area. The largest is Horry County, with 1,133.1 square miles of land.
What counties border Marlboro County?
Marlboro County shares a land border with Dillon County, Chesterfield County, Darlington County, Scotland County, North Carolina, Richmond County, North Carolina, Florence County, and Robeson County, North Carolina.
What is the population of Marlboro County?
The Census Bureau estimates Marlboro County had 25,488 residents on July 1, 2025, ranking #1,653 of 3,222 county equivalents. That is 53 people per square mile of land.
What is the county seat of Marlboro County?
The county seat of Marlboro County is Bennettsville.
What cities and towns are in Marlboro County?
Marlboro County has 5 incorporated places. The most populous are Bennettsville city, McColl town, Clio town, Blenheim town, and Tatum town; 15,195 residents live outside any incorporated place.
Is Marlboro County part of a metropolitan area?
No. Marlboro County is outside every metropolitan and micropolitan statistical area in the July 2023 OMB delineation.
How many ZIP codes are in Marlboro County?
8 ZIP Code Tabulation Areas have land in Marlboro County, and 6 of them have most of their land inside the county. Census ZIP Code Tabulation Areas approximate USPS ZIP Code areas.
How does Marlboro County compare with U.S. states?
It has less land than every state. Rhode Island, the smallest, has 2.2 times as much land.
How many acres of land are in Marlboro County?
The land measurement converts to approximately 307,119 acres. Including water, total area is approximately 310,700 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.