Greencastle is a city located in Pennsylvania. With a 2020 population of 4,000, it is the 249th largest city in Pennsylvania and the 5402nd largest city in the United States. Greencastle is currently declining at a rate of -0.05% annually but its population has increased by 0.10% since the most recent census, which recorded a population of 3,996 in 2010. Greencastle reached it's highest population of 4,026 in 2014. Spanning over 2 miles, Greencastle has a population density of 2,520 people per square mile.
The average household income in Greencastle is $73,093 with a poverty rate of 3.26%. The median rental costs in recent years comes to $858 per month, and the median house value is $170,700. The median age in Greencastle is 39.4 years, 34.8 years for males, and 41.8 years for females. For every 100 females there are 95.7 males.