|Elevation||371 ft (113.1 m)|
|Area||3.7 sq mi (9.6 km2)|
|- land||3.7 sq mi (10 km2)|
|- water||0.0 sq mi (0 km2), 0%|
|Density||3,815.5 / sq mi (1,473.2 / km2)|
|- summer (DST)||EDT (UTC-4)|
The population of Fullerton was 14,925 at the 2010 census.
Originally known as Ferndale, the town was located on tracts of land originally settled by Giles Windsor (1767), Stephen Snyder (1786) and Jacob Yundt (1826). In 1895, the town was renamed "Fullerton" in honor of local businessman James W. Fuller Jr., who had purchased the railroad car wheel factory of Frederick & Company in 1865 and operated it as McKee, Fuller & Co. and later the Lehigh Car, Wheel & Axle Works. Fuller laid out the hamlet in 1870, and by 1883 it was a thriving company-town with a population in excess of 1,500 men and their families. When the Lehigh Valley cement industry exploded in the early 1900s, Fuller's company prospered by providing machinery to the mills in the region, and the town supplied the workforce for both his factories, and the numerous mills and quarries operating in the immediate area.
Fullerton is located at (40.631297, -75.480215).
According to the United States Census Bureau, the CDP has a total area of 3.7 square miles (9.6 km2), of which, 3.7 square miles (9.6 km2) of it is land and 0.27% is water.
As of the census of 2000, there were 14,268 people, 6,224 households, and 3,827 families residing in the CDP. The population density was 3,815.5 people per square mile (1,473.0/km²). There were 6,484 housing units at an average density of 1,733.9/sq mi (669.4/km²). The racial makeup of the CDP was 86.09% White, 3.88% African American, 0.16% Native American, 5.52% Asian, 0.07% Pacific Islander, 2.57% from other races, and 1.70% from two or more races. Hispanic or Latino of any race were 6.15% of the population.
Ancestries: German (28.3%), Italian (11.8%), Irish (10.8%), Arab (5.6%), Slovak (5.3%), English (5.0%). 
There were 6,224 households, out of which 24.2% had children under the age of 18 living with them, 48.7% were married couples living together, 9.1% had a female householder with no husband present, and 38.5% were non-families. 31.7% of all households were made up of individuals, and 11.2% had someone living alone who was 65 years of age or older. The average household size was 2.27 and the average family size was 2.87.
In the CDP the population was spread out, with 19.6% under the age of 18, 8.2% from 18 to 24, 31.3% from 25 to 44, 21.9% from 45 to 64, and 19.0% who were 65 years of age or older. The median age was 39 years. For every 100 females there were 92.3 males. For every 100 females age 18 and over, there were 89.0 males.
The median income for a household in the CDP was $43,048, and the median income for a family was $50,147. Males had a median income of $40,305 versus $27,230 for females. The per capita income for the CDP was $22,164. About 4.6% of families and 7.3% of the population were below the poverty line, including 8.3% of those under age 18 and 6.3% of those age 65 or over.
- Gensey, Karen L. (2004). Whitehall, Pennsylvania: The Golden Strip of the Lehigh Valley. Kutztown Publishing Company. OCLC 262464697.
- Roberts, Charles Rhoads; Rev. John Baer Stoudt; Rev. Thomas H. Krick; William J. Dietrich (1914). History of Lehigh County Pennsylvania and a Genealogical and Biographical Records of its Families 1. Lehigh Valley Publishing Company.
- Roberts, Charles R. (1936). "Place Names of Lehigh County and Their Origin". Proceedings: Lehigh County Historical Society (Allentown, Pennsylvania: Lehigh County Historical Society).
- Gensey, p. 17
- Gensey, p. 94
- Roberts, Charles R. (1936). "Place Names of Lehigh County and Their Origin". Proceedings: Lehigh County Historical Society (Allentown, Pennsylvania: Lehigh County Historical Society). Page 11.
- Staff (2010-07-09). "National Register Information System". National Register of Historic Places. National Park Service.
- "US Gazetteer files: 2010, 2000, and 1990". United States Census Bureau. 2011-02-12. Retrieved 2011-04-23.
- "American FactFinder". United States Census Bureau. Retrieved 2008-01-31.