Major highways

Adjacent counties

• Ozark County, Missouri (northwest)
• Howell County, Missouri (north)
• Oregon County, Missouri (northeast)
• Sharp County (east)
• Izard County (south)
• Baxter County (west)

2020 census

As of the 2020 United States census, there were 12,075 people, 4,973 households, and 3,278 families residing in the county.

2000 census

As of the 2000 census,^[13] there were 11,642 people, 4,810 households, and 3,511 families residing in the county. The population density was 19 people per square mile (7.3 people/km²). There were 5,973 housing units at an average density of 10 units per square mile (3.9 units/km²). The racial makeup of the county was 97.67% White, 0.20% Black or African American, 0.67% Native American, 0.21% Asian, 0.06% from other races, and 1.19% from two or more races. 0.53% of the population were Hispanic or Latino of any race.

There were 4,810 households, out of which 27.40% had children under the age of 18 living with them, 62.40% were married couples living together, 7.80% had a female householder with no husband present, and 27.00% were non-families. 24.40% of all households were made up of individuals, and 12.80% had someone living alone who was 65 years of age or older. The average household size was 2.39 and the average family size was 2.83.

In the county, the population was spread out, with 22.80% under the age of 18, 6.40% from 18 to 24, 23.70% from 25 to 44, 27.00% from 45 to 64, and 20.20% who were 65 years of age or older. The median age was 43 years. For every 100 females there were 96.00 males. For every 100 females age 18 and over, there were 93.10 males.

The median income for a household in the county was $25,529, and the median income for a family was $29,952. Males had a median income of $22,213 versus $18,066 for females. The per capita income for the county was $15,712. About 12.70% of families and 16.30% of the population were below the poverty line, including 20.10% of those under age 18 and 12.70% of those age 65 or over.

Cities

• Ash Flat
• Cherokee Village
• Hardy
• Horseshoe Bend
• Mammoth Spring
• Salem (county seat)

Town

• Viola

Unincorporated communities

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 Fulton County are listed below; listed in parentheses are the cities, towns, and/or census-designated places that are fully or partially inside the township. ^[15][16]