Elysburg is a census-designated place (CDP) in Northumberland County, Pennsylvania, United States. The population was 2,067 at the 2000 census. The area's biggest attraction is Knoebels Amusement Park, which has two wooden roller coasters.
As of the census of 2000 there were 3,937 people, 1,746 households, and 1,188 families residing in the CDP. The population density was 708.4 people per square mile (273.3/km²). There were 909 housing units at an average density of 311.5/sq mi (120.2/km²). The racial makeup of the CDP was 99.4% White, 0.1% African American, 0.1% Native American, 0.2% Asian, and 0.2% from two or more races. Hispanic or Latino of any race were 0.5% of the population.
There were 855 households out of which 29.9% had children under the age of 18 living with them, 60.5% were married couples living together, 8.0% had a female householder with no husband present, and 30.6% were non-families. 28.0% of all households were made up of individuals and 15.6% had someone living alone who was 65 years of age or older. The average household size was 2.35 and the average family size was 2.86.