Mifflinburg is a city located in Union County Pennsylvania. With a 2020 population of 3,453, it is the 277th largest city in Pennsylvania and the 5807th largest city in the United States . Mifflinburg is currently declining at a rate of -0.32% annually and its population has decreased by -2.46% since the most recent census, which recorded a population of 3,540 in 2010. Mifflinburg reached it's highest population of in . Spanning over 2 miles, Mifflinburg has a population density of 1,914 people per square mile.
The average household income in Mifflinburg is $62,094 with a poverty rate of 9.89%. The median rental costs in recent years comes to $749 per month, and the median house value is $150,500. The median age in Mifflinburg is 43.8 years, 40.4 years for males, and 50.4 years for females.