As of 2000, the population is 489,656. It was named for the wife of Cecil Calvert, the second Baron of Baltimore, Lady Anne Arundell or Arundel. Its county seat is Annapolis, which is also the capital of the state. It is pronounced AnnaRUNdul.
This county is a part of the Washington-Baltimore Metropolitan Area.
Other entities, such as the United States Postal Service, use a different selection of local place names. In all these cases, since the places are unincorporated, the boundaries are determined by the classifying authority.
According to the U.S. Census Bureau, the county has a total area of 1,523 km² (588 mi²). 1,077 km² (416 mi²) of it is land and 445 km² (172 mi²) of it is water. The total area is 29.25% water.
There are 178,670 households out of which 34.90% have children under the age of 18 living with them, 57.20% are married couples living together, 11.10% have a female householder with no husband present, and 27.70% are non-families. 21.30% of all households are made up of individuals and 6.40% have someone living alone who is 65 years of age or older. The average household size is 2.65 and the average family size is 3.09.
In the county the population is spread out with 25.20% under the age of 18, 8.10% from 18 to 24, 32.80% from 25 to 44, 23.90% from 45 to 64, and 10.00% who are 65 years of age or older. The median age is 36 years. For every 100 females there are 99.10 males. For every 100 females age 18 and over, there are 97.10 males.
The median income for a household in the county is $61,768, and the median income for a family is $69,019. Males have a median income of $43,747 versus $32,348 for females. The per capita income for the county is $27,578. 5.10% of the population and 3.60% of families are below the poverty line. Out of the total people living in poverty, 6.30% are under the age of 18 and 5.80% are 65 or older.