Mifflinburg is a very small borough located in the state of Pennsylvania. With a population of 3,441 people and two associated neighborhoods, Mifflinburg is the 434th largest community in Pennsylvania.

In terms of college education, Mifflinburg is somewhat better educated than the 21.84% who have a 4-year degree or higher in the typical US community: 28.64% of adults 25 and older in the borough have at least a bachelor's degree.

The per capita income in Mifflinburg in 2022 was $32,278, which is lower middle income relative to Pennsylvania, and middle income relative to the rest of the US. This equates to an annual income of $129,112 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.