As of the census of 2000, there were 259,903 people, 93,772 households, and 72,110 families residing in the county. The population density was 610 people per square mile (236/km²).
A more recent 2006 estimate puts the population of Chesterfield County at 306,000 - a growth of over 35,000 people since 2000.
There were 97,707 housing units at an average density of 230 per square mile (89/km²). The racial makeup of the county was 65.44% White, 32.23% Black or African American, 0.33% Native American, 2.37% Asian, 0.04% Pacific Islander, 1.34% from other races, and 1.41% from two or more races. 2.93% of the population were Hispanic or Latino of any race.
There were 93,772 households out of which 40.70% had children under the age of 18 living with them, 62.20% were married couples living together, 11.20% had a female householder with no husband present, and 23.10% were non-families. 18.50% of all households were made up of individuals and 4.80% had someone living alone who was 65 years of age or older. The average household size was 2.73 and the average family size was 3.11.
In the county, the population was spread out with 28.30% under the age of 18, 7.70% from 18 to 24, 31.20% from 25 to 44, 24.90% from 45 to 64, and 8.10% who were 65 years of age or older. The median age was 36 years. For every 100 females there were 95.00 males. For every 100 females age 18 and over, there were 91.30 males.
The median income for a household in the county was $58,537, and the median income for a family was $65,058. Males had a median income of $43,030 versus $30,518 for females. The per capita income for the county was $25,286. About 3.30% of families and 4.50% of the population were below the poverty line, including 5.60% of those under age 18 and 3.40% of those age 65 or over.