Stone County is part of the Gulfport–Biloxi, Mississippi, Metropolitan Statistical Area.
As of the census of 2000, there were 13,622 people, 4,747 households, and 3,626 families residing in the county. The population density was 31 people per square mile (12/km²). There were 5,343 housing units at an average density of 12 per square mile (5/km²). The racial makeup of the county was 79.42% White, 19.18% Black or African American, 0.29% Native American, 0.16% Asian, 0.03% Pacific Islander, 0.23% from other races, and 0.70% from two or more races. 1.25% of the population were Hispanic or Latino of any race.
There were 4,747 households out of which 37.30% had children under the age of 18 living with them, 58.80% were married couples living together, 13.30% had a female householder with no husband present, and 23.60% were non-families. 20.60% of all households were made up of individuals and 8.90% had someone living alone who was 65 years of age or older. The average household size was 2.72 and the average family size was 3.13.
In the county the population was spread out with 26.80% under the age of 18, 12.20% from 18 to 24, 27.40% from 25 to 44, 22.40% from 45 to 64, and 11.10% who were 65 years of age or older. The median age was 34 years. For every 100 females there were 98.20 males. For every 100 females age 18 and over, there were 96.00 males.
The median income for a household in the county was $30,495, and the median income for a family was $36,856. Males had a median income of $26,259 versus $21,228 for females. The per capita income for the county was $14,693. About 14.50% of families and 17.50% of the population were below the poverty line, including 23.10% of those under age 18 and 14.30% of those age 65 or over. Since Hurricane Katrina in August 2005 the population of Stone county has increased by about 40% overall in previously undeveloped areas such as the Beatrice community which now has several new property owners and homes. Industry in the area is at a standstill or decreasing due to lack of natural resources excluding timber and distance of travel being situated in a rural geographical area compared to other Mississippi coastal counties.