Major highways

• U.S. Highway 49
• Highway 1
• Highway 39
• Highway 85

Adjacent counties

• Lee County (north)
• Tunica County, Mississippi (northeast)
• Coahoma County, Mississippi (east)
• Bolivar County, Mississippi (southeast)
• Desha County (south)
• Arkansas County (southwest)
• Monroe County (northwest)

National protected areas

• St. Francis National Forest (part)
• White River National Wildlife Refuge (part)

2020 census

As of the 2020 United States Census, there were 16,568 people, 7,485 households, and 4,836 families residing in the county.

2010 census

As of the 2010 census, there were 21,757 people living in the county. 63.1% were Black or African American, 35.0% White, 0.3% Asian, 0.2% Native American, 0.4% of some other race and 0.9% of two or more races. 1.3% were Hispanic or Latino (of any race).

2000 census

As of the 2000 census,^[13] there were 26,445 people, 9,711 households, and 6,768 families living in the county. The population density was 38 people per square mile (15 people/km²). There were 10,859 housing units at an average density of 16 per square mile (6.2/km²). The racial makeup of the county was 59.04% Black or African American, 39.25% White, 0.43% from other races, 0.32% Asian, 0.17% Native American, 0.01% Pacific Islander, and 0.78% from two or more races. 1.44% of the population were Hispanic or Latino of any race. At over 58% of the county's population, Phillips County has the highest percentage of African Americans in the state of Arkansas.^[14]

There were 9,711 households, out of which 34.20% had children under the age of 18 living with them, 40.30% were married couples living together, 25.10% had a female householder with no husband present, and 30.30% were non-families. 27.60% of all households were made up of individuals, and 13.00% had someone living alone who was 65 years of age or older. The average household size was 2.69 and the average family size was 3.29.

In the county, the population was spread out, with 32.20% under the age of 18, 9.40% from 18 to 24, 23.20% from 25 to 44, 21.20% from 45 to 64, and 13.90% who were 65 years of age or older. The median age was 33 years. For every 100 females there were 84.70 males. For every 100 females age 18 and over, there were 77.70 males.

The median income for a household in the county was $22,231, and the median income for a family was $26,570. Males had a median income of $24,675 versus $17,520 for females. The per capita income for the county was $12,288. About 28.70% of families and 32.70% of the population were below the poverty line, including 45.50% of those under age 18 and 26.20% of those age 65 or over.

For the period 2000–2009, the Helena-West Helena statistical area lost 20.89% of its population, the largest decline of any statistical area in the country.

Cities

• Elaine
• Helena–West Helena (county seat)
• Lake View
• Marvell

Town

• Lexa

Unincorporated places

• Barton
• Modoc
• Poplar Grove
• Lambrook

Townships

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 Phillips County are listed below; listed in parentheses are the cities, towns, and/or census-designated places that are fully or partially inside the township. ^[22][23]