The borough is 16 miles (26 km) south of Bethlehem and 29 miles (47 km) north of Philadelphia, making Quakertown a border town of both the Delaware Valley and Lehigh Valley metropolitan areas. Quakertown is considered part of the Allentown–Bethlehem urbanized area and the Philadelphia–Camden–Vineland (PA–NJ–DE) MSA.
As of the census of 2000, there were 8,931 people, 3,421 households, and 2,251 families residing in the borough. The population density was 4,424.7 people per square mile (1,707.1/km²). There were 3,631 housing units at an average density of 1,798.9/sq mi (694.0/km²). The racial makeup of the borough was 94.46% White, 1.20% African American, 0.13% Native American, 1.51% Asian, 0.06% Pacific Islander, 1.58% from other races, and 1.06% from two or more races. Hispanic or Latino of any race were 2.88% of the population.
There were 3,421 households out of which 32.9% had children under the age of 18 living with them, 50.7% were married couples living together, 10.5% had a female householder with no husband present, and 34.2% were non-families. 28.3% of all households were made up of individuals and 11.9% had someone living alone who was 65 years of age or older. The average household size was 2.52 and the average family size was 3.11.
In the borough the population was spread out with 25.5% under the age of 18, 7.9% from 18 to 24, 32.2% from 25 to 44, 19.1% from 45 to 64, and 15.3% who were 65 years of age or older. The median age was 36 years. For every 100 females there were 95.9 males. For every 100 females age 18 and over, there were 92.1 males.
The median income for a household in the borough was $41,942, and the median income for a family was $51,194. Males had a median income of $33,697 versus $26,988 for females. The per capita income for the borough was $20,562. About 3.7% of families and 5.9% of the population were below the poverty line, including 7.0% of those under age 18 and 6.7% of those age 65 or over.
Quakertown has a public general aviation airport, simply named Quakertown Airport. The airport is not located in the Quakertown borough itself, but in neighboring Milford Township.