Mifflinburg is a very small borough located in the state of Pennsylvania. With a population of 3,462 people and two associated neighborhoods, Mifflinburg is the 434th largest community in Pennsylvania.

The population of Mifflinburg overall has a level of education that is slightly above the US average for all US cities and towns of 21.84%. Of adults 25 and older in Mifflinburg, 23.71% have at least a bachelor's degree.

The per capita income in Mifflinburg in 2022 was $32,492, which is middle income relative to Pennsylvania and the nation. This equates to an annual income of $129,968 for a family of four. However, Mifflinburg contains both very wealthy and poor people as well.

The people who call Mifflinburg home describe themselves as belonging to a variety of racial and ethnic groups. The greatest number of Mifflinburg residents report their race to be White, followed by Black or African-American. Important ancestries of people in Mifflinburg include German, Italian, Irish, English, and Polish.

The most common language spoken in Mifflinburg is English. Other important languages spoken here include Italian and Polish.