Greencastle is a city located in Franklin County Pennsylvania. With a 2020 population of 3,964, it is the 249th largest city in Pennsylvania and the 5443rd largest city in the United States . Greencastle is currently declining at a rate of -0.28% annually and its population has decreased by -0.80% since the most recent census, which recorded a population of 3,996 in 2010. Greencastle reached it's highest population of in . Spanning over 2 miles, Greencastle has a population density of 2,497 people per square mile.
The average household income in Greencastle is $74,221 with a poverty rate of 4.04%. The median rental costs in recent years comes to $866 per month, and the median house value is $172,700. The median age in Greencastle is 39 years, 33.7 years for males, and 42 years for females.