As of the census of 2000, there were 241,767 people, 81,954 households, and 63,104 families residing in the county. The population density was 174 people per square mile (67/km²). There were 90,628 housing units at an average density of 65 per square mile (25/km²). The racial makeup of the county was 77.09% White, 8.50% Black or African American, 0.53% Native American, 2.00% Asian, 0.03% Pacific Islander, 9.63% from other races, and 2.22% from two or more races. 22.78% of the population were Hispanic or Latino of any race. 12.1% were of German, 11.2% American and 7.2% English ancestry according to Census 2000. 79.0% spoke English and 18.1% Spanish as their first language.
There were 81,955 households out of which 40.80% had children under the age of 18 living with them, 62.20% were married couples living together, 10.40% had a female householder with no husband present, and 23.00% were non-families. 19.10% of all households were made up of individuals and 6.40% had someone living alone who was 65 years of age or older. The average household size was 2.82 and the average family size was 3.23.
In the county, the population was spread out with 28.60% under the age of 18, 8.60% from 18 to 24, 32.40% from 25 to 44, 21.50% from 45 to 64, and 8.80% who were 65 years of age or older. The median age was 34 years. For every 100 females there were 106.80 males. For every 100 females age 18 and over, there were 107.40 males.
The median income for a household in the county was $48,632, and the median income for a family was $55,282. Males had a median income of $42,193 versus $27,728 for females. The per capita income for the county was $20,021. About 8.10% of families and 10.20% of the population were below the poverty line, including 12.60% of those under age 18 and 8.70% of those age 65 or over.
Brazoria County Airport in central unincorporated Brazoria County is the county's sole publicly-owned airport.
The following airports, located in the county, are privately-owned and for public use:
The closest airport with regularly scheduled commercial service is Houston's William P. Hobby Airport located in Houston in adjacent Harris County. The closest airport with regularly scheduled international commercial service is George Bush Intercontinental Airport in Houston in Harris County.