Mississippi County is the easternmost county in the U.S. state of Arkansas. As of the 2020 census, the population was 40,685. There are two county seats, Blytheville and Osceola. The county is named for the Mississippi River which borders the county to the east. Mississippi County is part of the First Congressional District in Arkansas.

The Blytheville, AR Micropolitan Statistical Area includes all of Mississippi County.

Extant early settlements include the Eaker Site and the Sherman Mound.

Local oral tradition held that prior to the major earthquakes of 1812, the lands in Mississippi County were higher in elevation compared to now and were not prone to flooding. Though the earthquake was named for New Madrid, Missouri, as that was the only town in the area with any population, the actual epicenter of the quake was three miles below what is now Blytheville, Arkansas.

American settlers were recorded in the area as early as 1828. These early settlers include John Troy, the first Mississippi County Judge and namesake of Troy township and G.C. Barfield, the first county surveyor and namesake of Barfield Landing.

Mississippi County was created on November 1, 1833, when it was split off from Craighead County. By 1836, when Arkansas achieved statehood, the county's white population had slightly increased and the local Native population was pushed in the eastern part of the county, towards what is now Big Lake. The first county seat was a small community called Cornwall, which was located at on the banks of the Mississippi River, on the remains of an old Spanish "encampment." Osceola was named as the County Seat in 1833, and later incorporated in 1843.

The Federal Swamp Act of 1850 granted federally controlled swamp lands to their respective state governments for sale. According to the 1852 surveyor general's report, Mississippi County had the largest amount of swamp and "Sunken" lands of any county in the country.

Following the American Civil War, Mississippi County was one of 10 counties in Arkansas put under martial law due to increased activity from the Ku Klux Klan. In 1872, a series of racial and political confrontations known as the Black Hawk War took place. The genesis of this was the murder of "Carpetbagger" Charles Fitzpatrick by the county Sherriff J.B. Murray over Fitzpatrick's allegations of Murray's embezzlement of school funds.

During World War 2, a B-25 pilot training school was constructed at Blytheville, with satellite landing strips at Manilla and in the Missouri Bootheel. The facility was later reopened in 1954 at Blytheville Air Force Base, and hosted a squadron of B-52s from 1959 to 1992.

In 1987, Nucor Steel opened a steel plant at Barfield Landing on the Mississippi River. In 2014, U.S. Steel opened a steel plant at Osceola. Mississippi County is now reportedly the largest steel producing county in America.

According to the U.S. Census Bureau, the county has a total area of 920 square miles (2,400 km), of which 901 square miles (2,330 km) is land and 19 square miles (49 km) (2.1%) is water.

• Big Lake National Wildlife Refuge

Historical population

Census	Pop.	Note	%±
1840	1,410		—
1850	2,368		67.9%
1860	3,895		64.5%
1870	3,633		−6.7%
1880	7,332		101.8%
1890	11,635		58.7%
1900	16,384		40.8%
1910	30,468		86.0%
1920	47,320		55.3%
1930	69,289		46.4%
1940	80,217		15.8%
1950	82,375		2.7%
1960	70,174		−14.8%
1970	62,060		−11.6%
1980	59,517		−4.1%
1990	57,525		−3.3%
2000	51,979		−9.6%
2010	46,480		−10.6%
2020	40,685		−12.5%
2023 (est.)	38,663		−5.0%
U.S. Decennial Census 1790–1960 1900–1990 1990–2000 2010–2020 2020

Mississippi County Racial Composition

Race	Num.	Perc.
White	22,861	56.19%
Black or African American	14,251	35.03%
Native American	67	0.16%
Asian	242	0.59%
Pacific Islander	3	0.01%
Other/Mixed	1,490	3.66%
Hispanic or Latino	1,771	4.35%

As of the 2020 United States Census, there were 40,685 people, 16,389 households, and 10,635 families residing in the county.

As of the 2010 census, there were 46,480 people living in the county. The racial makeup of the county was 60.5% White, 33.9% Black, 0.3% Native American, 0.5% Asian, <0.0% Pacific Islander, 0.1% from some other race and 1.2% from two or more races. 3.6% were Hispanic or Latino of any race.

As of the 2000 census, there were 51,979 people, 19,349 households, and 13,911 families living in the county. The population density was 58 people per square mile (22 people/km). There were 22,310 housing units at an average density of 25 units per square mile (9.7 units/km). The racial makeup of the county was 64.45% White, 32.70% Black or African American, 0.26% Native American, 0.38% Asian, 0.03% Pacific Islander, 1.07% from other races, and 1.12% from two or more races. 2.25% of the population were Hispanic or Latino of any race.

There were 19,349 households, out of which 36.00% had children under the age of 18 living with them, 50.00% were married couples living together, 17.40% had a female householder with no husband present, and 28.10% were non-families. 24.70% of all households were made up of individuals, and 10.70% had someone living alone who was 65 years of age or older. The average household size was 2.64 and the average family size was 3.15.

In the county, the population was spread out, with 29.60% under the age of 18, 9.90% from 18 to 24, 27.50% from 25 to 44, 20.80% from 45 to 64, and 12.20% who were 65 years of age or older. The median age was 33 years. For every 100 females there were 91.80 males. For every 100 females age 18 and over, there were 87.70 males.

The median income for a household in the county was $27,479, and the median income for a family was $32,648. Males had a median income of $29,645 versus $19,782 for females. The per capita income for the county was $13,978. About 19.00% of families and 23.00% of the population were below the poverty line, including 31.10% of those under age 18 and 19.80% of those age 65 or over.

The Mississippi County Judge is John Alan Nelson. Formerly a traditionally Democratic area, Mississippi County has voted Republican in the past five presidential elections.

United States presidential election results for Mississippi County, Arkansas

Year	Republican		Democratic		Third party(ies)
	No.	%	No.	%	No.	%
2024	6,963	64.97%	3,574	33.35%	180	1.68%
2020	7,296	59.12%	4,558	36.93%	488	3.95%
2016	7,061	53.48%	5,670	42.94%	473	3.58%
2012	6,603	49.37%	6,467	48.35%	305	2.28%
2008	6,976	49.79%	6,667	47.59%	367	2.62%
2004	6,121	43.25%	7,593	53.65%	439	3.10%
2000	5,199	41.31%	7,107	56.47%	280	2.22%
1996	3,919	29.36%	8,301	62.19%	1,127	8.44%
1992	4,697	29.43%	10,046	62.94%	1,219	7.64%
1988	7,841	52.67%	6,759	45.40%	288	1.93%
1984	10,180	57.30%	7,548	42.49%	38	0.21%
1980	7,170	43.67%	8,908	54.26%	339	2.06%
1976	6,009	36.80%	10,292	63.03%	27	0.17%
1972	10,931	74.73%	3,544	24.23%	152	1.04%
1968	4,369	28.17%	4,993	32.19%	6,147	39.64%
1964	6,213	41.67%	8,678	58.20%	20	0.13%
1960	4,983	47.08%	5,138	48.54%	464	4.38%
1956	4,269	38.97%	6,428	58.68%	258	2.36%
1952	4,586	39.65%	6,968	60.24%	13	0.11%
1948	771	12.17%	3,763	59.40%	1,801	28.43%
1944	1,292	24.68%	3,938	75.22%	5	0.10%
1940	616	10.46%	5,257	89.24%	18	0.31%
1936	303	5.89%	4,835	93.94%	9	0.17%
1932	364	5.87%	5,776	93.12%	63	1.02%
1928	1,324	22.83%	4,451	76.75%	24	0.41%
1924	703	24.86%	2,039	72.10%	86	3.04%
1920	1,050	35.23%	1,809	60.70%	121	4.06%
1916	417	25.03%	1,249	74.97%	0	0.00%
1912	263	20.23%	767	59.00%	270	20.77%
1908	1,167	51.57%	930	41.10%	166	7.34%
1904	417	37.40%	689	61.79%	9	0.81%
1900	378	39.01%	591	60.99%	0	0.00%
1896	168	17.06%	815	82.74%	2	0.20%

The economy of Mississippi County transitioned from agriculture (especially cotton) to manufacturing (mostly steel production) beginning in the 1980s. Over $2.1 billion has been invested in plants and supporting infrastructure in the county, with major facilities being operated by Nucor and Big River Steel (a U.S. Steel company). As of 2021 Mississippi County is the second-largest steel producing county in the United States. The county's position near the center of the United States and along the Mississippi River allows the input for steel mills, scrap metal, to be shipped in on barges, often the most inexpensive method of shipping, and by railroad from Memphis. Company executives have also praised the work ethic of the rural farm families of the area as a natural fit for ironworkers.

Mississippi County is home to the following public school districts, listed in order of student population:

• Blytheville School District
• Osceola School District
• Gosnell School District
• Southern Mississippi County School District
• Manila School District
• Buffalo Island Central School District
• Armorel School District

The following school districts are based outside of the county but serve portions:

• East Poinsett County School District
• KIPP: Delta Public Schools
• Nettleton School District

Mississippi County is served by the Mississippi–Crittenden Regional Library System, which includes the Mississippi County Library System (central library) and 13 branch libraries in communities throughout the county.

FM

• FM 88.3 KBCM Blytheville
• FM 93.9 KAMJ Gosnell
• FM 96.3 KHLS Blytheville
• FM 103.7 KAIA K279BJ Blytheville
• FM 107.3 KOSE-FM Osceola

AM

• AM 860 KOSE Wilson

• NEA Town Courier, Newspaper, Blytheville, Arkansas
• The Osceola Times, Newspaper, Osceola, Arkansas

There are no television stations in Mississippi County, Arkansas. Mississippi County, Arkansas is placed in the Memphis, TN Television Market. Those stations include:

• ABC- WATN 24
• NBC- WMC 5
• CBS- WREG 3
• Fox- WHBQ 13
• PBS- WKNO 10
• CW- WLMT 30
• Ion WPXX 50

However some residents in county may watch stations from the Jackson, TN, Jonesboro, AR, or Little Rock, AR Television Markets.

• Armorel

Townships in Arkansas are the divisions of a county. Each township includes unincorporated areas; some may have incorporated cities or towns within part of their boundaries. Arkansas townships have limited purposes in modern times. However, the United States census does list Arkansas population based on townships (sometimes referred to as "county subdivisions" or "minor civil divisions"). Townships are also of value for historical purposes in terms of genealogical research. Each town or city is within one or more townships in an Arkansas county based on census maps and publications. The townships of Mississippi County are listed below; listed in parentheses are the cities, towns, and/or census-designated places that are fully or partially inside the township.

• Arkansas Highway 119 (1927–2022), former state highway in Mississippi County
• Island 35 Mastodon
• List of lakes in Mississippi County, Arkansas
• National Register of Historic Places listings in Mississippi County, Arkansas

• "Mississippi. I. A N. E. county of Arkansas" . The American Cyclopædia. 1879.

35°46′36″N 90°03′16″W / 35.77667°N 90.05444°W / 35.77667; -90.05444