Cinco Bayou is located at (30.421748, -86.609120).
According to the United States Census Bureau, the town has a total area of 0.2 square miles (0.5 km²), all of it land. The town is completely surrounded by the city of Fort Walton Beach, Florida.
There were 212 households out of which 15.1% had children under the age of 18 living with them, 27.8% were married couples living together, 7.1% had a female householder with no husband present, and 61.3% were non-families. 46.2% of all households were made up of individuals and 8.5% had someone living alone who was 65 years of age or older. The average household size was 1.77 and the average family size was 2.43.
In the town the population was spread out with 12.5% under the age of 18, 7.2% from 18 to 24, 43.0% from 25 to 44, 25.5% from 45 to 64, and 11.9% who were 65 years of age or older. The median age was 40 years. For every 100 females there were 96.4 males. For every 100 females age 18 and over, there were 93.0 males.
The median income for a household in the town was $28,036, and the median income for a family was $28,750. Males had a median income of $33,750 versus $21,250 for females. The per capita income for the town was $22,425. About 9.9% of families and 15.5% of the population were below the poverty line, including 25.4% of those under age 18 and 4.4% of those age 65 or over.