Medford Township was incorporated as a township by an Act of the New Jersey Legislature on March 1, 1847, from portions of Evesham Township, based on the results of a referendum held that day. Portions of the township were taken to form Shamong Township , Lumberton Township and Medford Lakes .
As of the census of 2000, there were 22,253 people, 7,946 households, and 6,285 families residing in the township. The population density was 566.0 people per square mile (218.5/km²). There were 8,147 housing units at an average density of 207.2/sq mi (80.0/km²). The racial makeup of the township was 96.74% White, 0.76% African American, 0.12% Native American, 1.47% Asian, 0.04% Pacific Islander, 0.28% from other races, and 0.59% from two or more races. Hispanic or Latino of any race were 1.13% of the population.
There were 7,946 households out of which 38.3% had children under the age of 18 living with them, 70.8% were married couples living together, 6.4% had a female householder with no husband present, and 20.9% were non-families. 17.4% of all households were made up of individuals and 7.6% had someone living alone who was 65 years of age or older. The average household size was 2.77 and the average family size was 3.16.
In the township the population was spread out with 26.8% under the age of 18, 5.4% from 18 to 24, 26.7% from 25 to 44, 30.4% from 45 to 64, and 10.7% who were 65 years of age or older. The median age was 40 years. For every 100 females there were 93.9 males. For every 100 females age 18 and over, there were 90.1 males.
The median income for a household in the township was $103,865, and the median income for a family was $117,215. Males had a median income of $69,786 versus $37,012 for females. The per capita income for the township was $46,859. About 0.9% of families and 1.9% of the population were below the poverty line, including 2.1% of those under age 18 and 2.2% of those age 65 or over.
New Jersey Transit provides bus service to Philadelphia on the 406 bus route. Greyhound Lines provides nationwide service from nearby Mount Laurel.
The PATCO Speedline provides train access to Philadelphia with several stops convenient to Medford, including Ashland and Woodcrest. The River Line (New Jersey Transit) connects Trenton to Camden.