As of the census of 2000, there were 18,036 people, 5,872 households, and 4,474 families residing in the town. The population density was 628.3 people per square mile (242.6/km²). There were 5,961 housing units at an average density of 207.7/sq mi (80.2/km²). The racial makeup of the town was 92.15% White, 1.16% African American, 0.13% Native American, 1.00% Asian, 0.01% Pacific Islander, 4.47% from other races, and 1.08% from two or more races. Hispanic or Latino of any race were 1.14% of the population.
There were 5,872 households out of which 42.3% had children under the age of 18 living with them, 61.8% were married couples living together, 10.8% had a female householder with no husband present, and 23.8% were non-families. 19.3% of all households were made up of individuals and 6.9% 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 3.22.
In the town the population was spread out with 27.0% under the age of 18, 12.6% from 18 to 24, 32.2% from 25 to 44, 20.5% from 45 to 64, and 7.8% who were 65 years of age or older. The median age was 33 years. For every 100 females there were 90.7 males. For every 100 females age 18 and over, there were 86.1 males.
The median income for a household in the town was $64,818, and the median income for a family was $71,848. Males had a median income of $51,133 versus $33,149 for females. The per capita income for the town was $23,876. About 2.2% of families and 4.0% of the population were below the poverty line, including 2.9% of those under age 18 and 12.9% of those age 65 or over.
The town is bisected southeast to northwest by Interstate 495, as well as Route 140 from north to south and Route 123 from southwest to northeast. Interstate 495's Exit 10 links the highway with Route 123. Exit 9 (Bay Street, Taunton) and Exit 11 (Route 140, Mansfield/Norton) are just over the town lines. Route 140 and Route 123 intersect at the center of town, by the town green. Although it is not officially signed as such, many fans attending concerts and events at the Comcast Center, just over the line in Mansfield along Route 140, reach the venue by driving along Route 123 to Route 140. The town is also a part of the Greater Attleboro Taunton Regional Transit Authority (or GATRA) bus line. The nearest MBTA station is Mansfield.