Cape St. Claire, a suburb of Annapolis, is a covenanted, unincorporated community as well as a census-designated place (CDP) in Anne Arundel County, Maryland, United States. While the community of Cape St. Claire lies entirely within the CDP and accounts for approximately 80% of the homes and residents, the CDP also includes the smaller communities of Atlantis, Walnut Ridge, Green Holly, and St. Claire Court. The population of the CDP was 8,747 at the 2010 census.
Cape St. Claire is located at 39°2′34″N 76°26′44″W / 39.04278°N 76.44556°W / 39.04278; -76.44556 (39.042910, −76.445623). The CDP is bounded to the east by the Little Magothy River, to the north by the Magothy River, to the west by Deep Creek, and to the south by College Parkway. U.S. Route 50 runs just to the south of the CDP, leading west 7 miles (11 km) to Annapolis and east 3 miles (5 km) to the Chesapeake Bay Bridge.
According to the United States Census Bureau, the CDP has a total area of 2.5 square miles (6.5 km), of which 2.0 square miles (5.2 km) is land and 0.54 square miles (1.4 km), or 20.72%, is water.
As of the census of 2000, there were 8,022 people, 2,857 households, and 2,179 families residing in the CDP. The population density was 4,066.9 people per square mile (1,572.2/km²). There were 2,932 housing units at an average density of 1,486.4/sq mi (574.6/km²). The racial makeup of the CDP was 92.98% White, 3.84% African American, 0.11% Native American, 1.13% Asian, 0.07% Pacific Islander, 0.65% from other races, and 1.21% from two or more races. Hispanic or Latino of any race were 2.13% of the population.
There were 2,856 households out of which 41.7% had children under the age of 18 living with them, 62.5% were married couples living together, 10.3% had a female householder with no husband present, and 23.7% were non-families. 18.2% of all households were made up of individuals and 6.2% had someone living alone who was 65 years of age or older. The average household size was 2.79 and the average family size was 3.19.
In the CDP, the population was spread out with 28.6% under the age of 18, 6.4% from 18 to 24, 32.7% from 25 to 44, 25.2% from 45 to 64, and 7.1% who were 65 years of age or older. The median age was 36 years. For every 100 females, there were 98.3 males. For every 100 females age 18 and over, there were 93.1 males.
The median income for a household in the CDP was $72,000, and the median income for a family was $76,657. Males had a median income of $50,133 versus $32,212 for females. The per capita income for the CDP was $27,009. About 1.4% of families and 2.6% of the population were below the poverty line, including 2.2% of those under age 18 and 13.7% of those age 65 or over.