Warren County is a county located in the U.S. state of Mississippi. Its western border is formed by the Mississippi River. As of the 2020 census, the population was 44,722. Its county seat is Vicksburg. Established by legislative act of December 22, 1809, Warren County is named for American Revolutionary War officer Joseph Warren.

Part of the Mississippi Delta and the historic cotton culture, Warren County had major plantations. Vicksburg was an important river port. Today the county is included in the Vicksburg, MS Micropolitan Statistical Area, which is also included in the Jackson-Vicksburg-Brookhaven, MS Combined Statistical Area.

According to the U.S. Census Bureau, the county has a total area of 619 square miles (1,600 km), of which 589 square miles (1,530 km) is land and 30 square miles (78 km) (4.9%) is water.

The county exists in two sections, connected only by a narrow 500-foot wide section between Madison Parish, Louisiana and Issaquena County, Mississippi along the delta of the Yazoo River. This area was once along the Mississippi River, but has since become an oxbow lake and marsh and no roads traverse this strip of land. The community of Eagle Bend is in this area.

• Interstate 20
• U.S. Route 61
• U.S. Route 80
• Mississippi Highway 3
• Mississippi Highway 27

• Issaquena County (north)
• Yazoo County (northeast)
• Hinds County (east)
• Claiborne County (south)
• Tensas Parish, Louisiana (southwest)
• Madison Parish, Louisiana (west)

• Theodore Roosevelt National Wildlife Refuge (part)
• Vicksburg National Military Park (part)

Historical population

Census	Pop.	Note	%±
1810	1,114		—
1820	2,693		141.7%
1830	7,861		191.9%
1840	15,820		101.2%
1850	18,120		14.5%
1860	20,696		14.2%
1870	26,769		29.3%
1880	31,238		16.7%
1890	33,164		6.2%
1900	40,912		23.4%
1910	37,488		−8.4%
1920	33,362		−11.0%
1930	35,785		7.3%
1940	39,595		10.6%
1950	39,616		0.1%
1960	42,206		6.5%
1970	44,981		6.6%
1980	51,627		14.8%
1990	47,880		−7.3%
2000	49,644		3.7%
2010	48,773		−1.8%
2020	44,722		−8.3%
2023 (est.)	42,298		−5.4%
U.S. Decennial Census 1790-1960 1900-1990 1990-2000 2010-2013

Warren County by race as of 2020

Race	Num.	Perc.
White	20,909	46.75%
Black or African American	21,290	47.61%
Native American	67	0.15%
Asian	364	0.81%
Other/Mixed	1,216	2.72%
Hispanic or Latino	876	1.96%

As of the 2020 United States census, there were 44,722 people, 18,235 households, and 11,480 families residing in the county. In 2010, there were 48,773 people living in the county. 50.3% were White, 47.0% Black or African American, 0.8% Asian, 0.3% Native American, 0.7% of some other race and 0.9% of two or more races. 1.8% were Hispanic or Latino (of any race).

In 2000, there were 49,644 people, 18,756 households, and 13,222 families living in the county. The population density was 85 people per square mile (33 people/km). There were 20,789 housing units at an average density of 35 units per square mile (14 units/km). The racial makeup of the county was 54.97% White, 43.19% Black or African American, 0.23% Native American, 0.62% Asian, 0.02% Pacific Islander, 0.33% from other races, and 0.66% from two or more races. 1.04% of the population were Hispanic or Latino of any race.

2005 census estimates based on the American Community Survey suggested that non-Hispanic whites were 51.5% of Warren County's population. Warren County was the only county in Mississippi along the Mississippi River, in addition to Desoto, where whites made up a majority of the population. African Americans were 46.0% of the county's population. People identifying as of two or more races were 0.6%, less than in the previous ACS. The Latino population was 1.2% of the total for the county.

In 2000 there were 18,756 households, out of which 35.60% had children under the age of 18 living with them, 46.80% were married couples living together, 19.10% had a female householder with no husband present, and 29.50% were non-families. 25.80% of all households were made up of individuals, and 9.70% had someone living alone who was 65 years of age or older. The average household size was 2.61 and the average family size was 3.14.

In the county, the population was spread out, with 28.50% under the age of 18, 9.10% from 18 to 24, 28.40% from 25 to 44, 22.40% from 45 to 64, and 11.70% who were 65 years of age or older. The median age was 35 years. For every 100 females there were 88.30 males. For every 100 females age 18 and over, there were 84.40 males.

The median income for a household in the county was $35,056, and the median income for a family was $41,706. Males had a median income of $33,566 versus $21,975 for females. The per capita income for the county was $17,527. About 15.00% of families and 18.70% of the population were below the poverty line, including 27.80% of those under age 18 and 16.20% of those age 65 or over.

Warren County has the seventh highest per capita income in the state of Mississippi.

Warren County was historically Democratic until 1948, then was a Republican stronghold until 2008 (when it was narrowly carried by John McCain), and has recently become a bellwether. It voted for Barack Obama in 2012, Donald Trump in 2016, Joe Biden in 2020, and Donald Trump in 2024.Warren County is one of two counties (the other being Nash County, North Carolina) to alternate its presidential vote the last five elections.

Members are elected from each of the five supervisory districts. The Board of Supervisors guides and establishes policies for the county government. Members of the board of make decisions regarding economic development, public health and welfare and county roads.

United States presidential election results for Warren County, Mississippi

Year	Republican		Democratic		Third party(ies)
	No.	%	No.	%	No.	%
2024	9,407	51.41%	8,683	47.45%	208	1.14%
2020	10,365	49.23%	10,442	49.60%	246	1.17%
2016	9,767	50.30%	9,284	47.82%	365	1.88%
2012	10,457	48.89%	10,786	50.42%	148	0.69%
2008	11,152	51.24%	10,489	48.19%	123	0.57%
2004	11,356	57.69%	8,224	41.78%	103	0.52%
2000	10,892	58.49%	7,485	40.19%	246	1.32%
1996	9,261	47.77%	8,774	45.26%	1,350	6.96%
1992	10,209	49.61%	8,175	39.73%	2,194	10.66%
1988	12,507	62.01%	7,437	36.87%	226	1.12%
1984	12,959	60.99%	8,054	37.90%	235	1.11%
1980	10,151	56.00%	7,489	41.31%	488	2.69%
1976	8,699	55.39%	6,299	40.11%	707	4.50%
1972	10,420	71.97%	3,480	24.04%	578	3.99%
1968	2,392	16.95%	4,503	31.91%	7,217	51.14%
1964	7,409	81.96%	1,631	18.04%	0	0.00%
1960	2,277	34.57%	2,289	34.75%	2,021	30.68%
1956	2,419	45.40%	1,857	34.85%	1,052	19.74%
1952	3,458	59.38%	2,366	40.63%	0	0.00%
1948	245	5.88%	320	7.67%	3,605	86.45%
1944	304	8.67%	3,202	91.33%	0	0.00%
1940	192	5.92%	3,048	94.05%	1	0.03%
1936	122	3.63%	3,233	96.19%	6	0.18%
1932	169	6.47%	2,422	92.76%	20	0.77%
1928	530	16.07%	2,769	83.93%	0	0.00%
1924	328	15.46%	1,794	84.54%	0	0.00%
1920	161	12.80%	1,082	86.01%	15	1.19%
1916	73	5.69%	1,204	93.92%	5	0.39%
1912	55	4.11%	1,135	84.76%	149	11.13%

• Vicksburg (county seat and only municipality)

• Beechwood
• Bovina
• Eagle Bend
• Redwood

• Brunswick

All of the county is in the Vicksburg Warren School District.

The county is in the district of Hinds Community College. The college operates a Rankin Campus in Pearl.

• Sarah Gibson Humphreys (1830–1907), author and woman suffragist

• National Register of Historic Places listings in Warren County, Mississippi
• Joseph A. Biedenharn, first bottler of Coca-Cola

• Warren County, Mississippi

32°22′N 90°51′W / 32.36°N 90.85°W / 32.36; -90.85