The village of Ocean Grove is located in the town.
As of the census of 2000, there were 15,901 people, 5,888 households, and 4,539 families residing in the town. The population density was 689.4 people per square mile (266.2/km²). There were 6,070 housing units at an average density of 263.2/sq mi (101.6/km²). The racial makeup of the town was 97.91% White, 0.38% African American, 0.08% Native American, 0.36% Asian, 0.01% Pacific Islander, 0.27% from other races, and 1.00% from two or more races. Hispanic or Latino of any race were 0.60% of the population.
There were 5,888 households out of which 31.1% had children under the age of 18 living with them, 64.6% were married couples living together, 8.8% had a female householder with no husband present, and 22.9% were non-families. 19.6% of all households were made up of individuals and 10.2% had someone living alone who was 65 years of age or older. The average household size was 2.67 and the average family size was 3.06.
In the town the population was spread out with 22.2% under the age of 18, 6.7% from 18 to 24, 28.4% from 25 to 44, 27.0% from 45 to 64, and 15.7% who were 65 years of age or older. The median age was 40 years. For every 100 females there were 96.9 males. For every 100 females age 18 and over, there were 92.3 males.
The median income for a household in the town was $52,524, and the median income for a family was $60,567. Males had a median income of $40,056 versus $27,072 for females. The per capita income for the town was $21,776. About 3.4% of families and 4.9% of the population were below the poverty line, including 2.9% of those under age 18 and 11.0% of those age 65 or over.
The town is bisected by Interstate 195, U.S. Route 6, and State Routes 103, 118 and 136. Swansea has two exits off of I-195 serving the town, Exits 2 (Route 136) and 3 (Route 6 to Route 118). In addition, Exit 4 (Route 103) in Somerset provides quick access to the Ocean Grove neighborhood.
Swansea is the western terminus of the Southeastern Regional Transit Authority (SRTA) bus line. Regional bus service can be reached in Fall River, and the nearest regional rail service is in Providence. The nearest national airline service can be reached at T.F. Green Airport in Rhode Island, and international service can be reached at Logan International Airport in Boston.