Fredrickstown was the original village of present-day Hummelstown; it was established in 1762. The borough's current mayor is Bradley Miller.
As of the census of 2000, there were 4,360 people, 1,879 households, and 1,200 families residing in the borough. The population density was 3,233.6 people per square mile (1,247.0/km²). There were 1,953 housing units at an average density of 1,448.4/sq mi (558.6/km²). The racial makeup of the borough was 97.02% White, 0.32% African American, 0.02% Native American, 1.06% Asian, 0.07% Pacific Islander, 0.67% from other races, and 0.85% from two or more races. Hispanic or Latino of any race were 1.51% of the population.
There were 1,879 households out of which 29.3% had children under the age of 18 living with them, 49.1% were married couples living together, 10.5% had a female householder with no husband present, and 36.1% were non-families. 31.5% of all households were made up of individuals and 12.3% had someone living alone who was 65 years of age or older. The average household size was 2.32 and the average family size was 2.91.
In the borough the population was spread out with 23.6% under the age of 18, 7.4% from 18 to 24, 32.0% from 25 to 44, 21.1% from 45 to 64, and 15.9% who were 65 years of age or older. The median age was 38 years. For every 100 females there were 95.0 males. For every 100 females age 18 and over, there were 93.4 males.
The median income for a household in the borough was $41,625, and the median income for a family was $50,572. Males had a median income of $36,500 versus $27,547 for females. The per capita income for the borough was $21,394. About 4.2% of families and 6.7% of the population were below the poverty line, including 6.3% of those under age 18 and 7.2% of those age 65 or over.
Money Magazine (via their website and magazine) lists the median household income for Hummelstown to be $60,666 as of 2005, compared to the average in the United States which is $68,053 in 2005. The sales tax is 6.00%, compared to that of 6.77% nation-wide. The median house price is $154,815 compared to that of the nation average of $315,351.
In 2005, Hummelstown was named the 61st best town in the United States to live in, as voted on by The New York Times in association with Time, Life, and several other high-profile magazines on Money Magazine's website.