South Williamsport is a city located in Pennsylvania. With a 2020 population of 5,995, it is the 145th largest city in Pennsylvania and the 4283rd largest city in the United States. South Williamsport is currently declining at a rate of -0.89% annually and its population has decreased by -6.02% since the most recent census, which recorded a population of 6,379 in 2010. South Williamsport reached it's highest population of 7,153 in 1970. Spanning over 2 miles, South Williamsport has a population density of 3,157 people per square mile.
The average household income in South Williamsport is $63,873 with a poverty rate of 13.08%. The median rental costs in recent years comes to $897 per month, and the median house value is $136,800. The median age in South Williamsport is 39.4 years, 39.3 years for males, and 39.8 years for females. For every 100 females there are 90.6 males.