Bellmawr was incorporated as a borough on March 23, 1926, from portions of the now-defunct Centre Township, based on the results of a referendum held on April 21, 1926. The boroughs of Mount Ephraim, Runnemede and Lawnside were also created in the same two-day period.
Bellmawr is home to the main post office for the area, one of the largest in the state of New Jersey. In late October 2001 the office was closed due to possible anthrax contamination (see 2001 anthrax attacks). The office was re-opened several days later, in early November, after testing negative for anthrax.
According to the United States Census Bureau, the borough has a total area of 3.1 square miles (8.1 km²), of which, 3.0 square miles (7.8 km²) of it is land and 0.1 square miles (0.3 km²) of it (3.18%) is water.
There were 4,446 households out of which 26.9% had children under the age of 18 living with them, 52.3% were married couples living together, 12.6% had a female householder with no husband present, and 29.5% were non-families. 25.3% of all households were made up of individuals and 11.1% had someone living alone who was 65 years of age or older. The average household size was 2.53 and the average family size was 3.02.
In the borough the population was spread out with 20.8% under the age of 18, 8.4% from 18 to 24, 28.8% from 25 to 44, 24.6% from 45 to 64, and 17.5% who were 65 years of age or older. The median age was 40 years. For every 100 females there were 96.5 males. For every 100 females age 18 and over, there were 94.9 males.
The median income for a household in the borough was $44,653, and the median income for a family was $53,839. Males had a median income of $38,646 versus $27,050 for females. The per capita income for the borough was $19,863. About 2.6% of families and 4.0% of the population were below the poverty line, including 3.7% of those under age 18 and 5.2% of those age 65 or over.
The Mayor of the Borough of Bellmawr is Frank Filipek. Members of the Bellmawr Borough Council are John Bollinger, James D'Angelo, Louis DiAngelo, Peter DiGiambattista, Regina Piontkowski and Stephen Sauter.
For grades 9 through 12, public students attend Triton Regional High School (1,525 students), one of three high schools that are part of the Black Horse Pike Regional School District. The other communities in the district are Gloucester Township and Runnemede. The two other schools in the district are Highland Regional High School and Timber Creek Regional High School.
Annunciation Regional School is an elementary school that operates under the auspices of the Roman Catholic Diocese of Camden.
Various roads pass through Bellmawr, such as NJ 168, and very small portion of US 130. In terms of major highways, Bellmawr hosts the interchange with the "North-South Freeway" (NJ 42/I-76) and the 295 expressway. The New Jersey Turnpike passes through the southern part, hosting part of an interchange: Exit 3. Half of the interchange is Bellmawr, while the other part is in Runnemede. The Exit 3 toll gate is right on the line between Bellmawr and Runnemede, with a total of six lanes.