Adjacent counties

• Nevada County (north)
• Ouachita County (northeast)
• Union County (east)
• Claiborne Parish, Louisiana (southeast)
• Webster Parish, Louisiana (south)
• Lafayette County (west)

2020 census

As of the 2020 United States census, there were 22,801 people, 8,562 households, and 5,559 families residing in the county.

2000 census

As of the 2000 census,^[13] there were 25,603 people, 9,981 households, and 6,747 families residing in the county. The population density was 33 people per square mile (13 people/km²). There were 11,566 housing units at an average density of 15 units per square mile (5.8 units/km²). The racial makeup of the county was 62.08% White, 36.06% Black or African American, 0.26% Native American, 0.34% Asian, 0.03% Pacific Islander, 0.46% from other races, and 0.77% from two or more races. 1.05% of the population were Hispanic or Latino of any race.

There were 9,981 households, out of which 30.10% had children under the age of 18 living with them, 48.90% were married couples living together, 15.10% had a female householder with no husband present, and 32.40% were non-families. 29.20% of all households were made up of individuals, and 13.80% had someone living alone who was 65 years of age or older. The average household size was 2.45 and the average family size was 3.03.

In the county, the population was spread out, with 25.10% under the age of 18, 12.30% from 18 to 24, 25.30% from 25 to 44, 21.40% from 45 to 64, and 15.90% who were 65 years of age or older. The median age was 36 years. For every 100 females there were 90.90 males. For every 100 females age 18 and over, there were 86.70 males.

The median income for a household in the county was $27,640, and the median income for a family was $36,271. Males had a median income of $31,313 versus $20,099 for females. The per capita income for the county was $15,322. About 15.80% of families and 21.10% of the population were below the poverty line, including 28.70% of those under age 18 and 20.00% of those age 65 or over.

Major highways

• Future Interstate 69
• U.S. Highway 79
• U.S. Highway 82
• U.S. Highway 371
• Highway 19
• Highway 98
• Highway 160

Airports

Magnolia Municipal Airport is a public-use airport in Columbia County. It is owned by the city of Magnolia and located three nautical miles (6 km) southeast of its central business district.^[14]

Cities

• Magnolia (county seat)

Towns

• Emerson
• McNeil
• Taylor
• Waldo

Unincorporated community

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 Columbia County are listed below; listed in parentheses are the cities, towns, and/or census-designated places that are fully or partially inside the township. ^[16][17]

• Emerson (Emerson)
• McNeil (McNeil)
• Magnolia (Magnolia)
• Taylor (Taylor)
• Village
• Waldo (Waldo)