Mifflin County is a county in the U.S. state of Pennsylvania. As of the 2010 United States Census, the population was 46,682.^[1] Its county seat is Lewistown.^[2] The county was created on September 19, 1789, from parts of Cumberland County and Northumberland County. It was named for Thomas Mifflin, the first Governor of Pennsylvania.

Mifflin County comprises the Lewistown, PA Micropolitan Statistical Area.

The county terrain is formed by the folded Appalachian Mountain ridges which run from southwest to northeast across the county. The terrain slopes to the northeast,^[3] with its highest point (Broad Mtn) 1.25 mile (2 km) ENE from the county's NW corner, just south of the county's border with Centre County. It measures 2,339' (713m) ASL.^[4] The Juniata River flows northeast through the lower part of the county, exiting northeastward into Juniata County near Hawstone.^[5] The county has a total area of 415 square miles (1,070 km2), of which 411 square miles (1,060 km2) is land and 3.7 square miles (9.6 km2) (0.9%) is water.^[6]

Mifflin County is located in, and has its boundaries defined by, the Ridge-and Valley Appalachian Mountains of Pennsylvania. US Route 322, a major divided highway, connects the county to the rest of the state on its route between Harrisburg and State College. US Route 522 also connects the county to the rest of the state on its route between Selinsgrove and Mount Union.

As of the 2010 United States Census, there were 46,682 people and 18,743 households in the county. The population density was 113.6/sqmi (43.9/km²). There were 21,537 housing units at an average density of 52.4/sqmi (20.2/km²). The racial makeup of the county was 97.53% White, 0.64% Black or African American, 0.11% Native American, 0.36% Asian, 0.01% Pacific Islander, 0.31% from other races, and 1.03% from two or more races. 1.14% of the population were Hispanic or Latino of any race. 38.8% were of German, 19.2% American, 8.0% Irish and 7.5% English ancestry. 5.7% report speaking Pennsylvania German, Dutch, or German at home.^[12]

There were 18,743 households out of which 29.1% had children under the age of 18 living with them, 57.60% were married couples living together, 8.50% had a female householder with no husband present, and 29.90% were non-families. 26.00% of all households were made up of individuals and 13.20% had someone living alone who was 65 years of age or older. The average household size was 2.49 and the average family size was 2.99.

The county population contained 23.1% under the age of 18, 2.2% from 18 to 19, 5.1% from 20 to 24, 10.4% from 25 to 34, 20.1% from 35 to 49, 20.6% from 50 to 64, and 18.5% who were 65 years of age or older. The median age was 39 years. The population was 48.93% male, and 51.07% female.

The Amish community in Mifflin County, established in 1791, had a total population of 3,905 people (in 30 congregations) in 2017,^[13] or 8.5% of the county's population.

The dominant form of speech in Mifflin County is the Central Pennsylvania accent. Almost everyone in Mifflin County speaks English. The Amish and some Mennonites speak Pennsylvania German also known as Pennsylvania Dutch, a West Central German dialect, which is quite different from modern Standard German. The Amish and Mennonites also can speak English. Few non-Amish or Mennonites in Mifflin County today speak Pennsylvania German, but this was not true in the past.

The United States Office of Management and Budget^[14] has designated Mifflin County as the Lewistown, PA Micropolitan Statistical Area (µSA).^[15] As of the 2010 United States Census^[16] the micropolitan area ranked 10th most populous in the State of Pennsylvania and the 237th most populous in the United States with a population of 46,682.

In August 2016, then County Commissioner Lisa Nancollas, a Tea Party Republican, came under fire for anti-Islamic rhetoric posted to her campaign's Facebook account.^[17] She resigned from her position in April 2017, replaced by Rob Postal.^[18][19]

(as of 9 May 2017)

(as of 9 May 2017)

Mifflin County voters have been reliably Republican. In only one national election since 1940 has the county selected the Democratic Party candidate.

Major employers in Mifflin County include:

Most of the county is served by the Mifflin County School District, with the exception of Wayne Township and the boroughs of Newton-Hamilton and Kistler, which are part of the Mount Union Area School District.

Head Start is a federally and state funded preschool program for low income children. The program serves 3- and 4-year-olds. In order to participate the family income must be below federal poverty guidelines.

Mifflin County Academy of Science and Technology located in Lewistown provides post high school degrees in nursing, auto mechanics and electrical services and other technology driven careers.

The Lewistown branch of the South Hills School of Business and Technology offers associate degrees and other certifications in various areas of business, technology, and some health care. (Closed 2019)

The Penn State Learning Center in Lewistown offers both two-year and four-year degrees. Recently, the Learning Center opened a state-of-the-art science lab to be used by students attending the Lewistown Hospital School of Nursing.

Mifflin County does not have a local television station but it is provided with local coverage from the following stations outside of the county from the Harrisburg, Altoona and State College markets:

Under Pennsylvania law, there are four types of incorporated municipalities: cities, boroughs, townships, and, in at most two cases, towns.

Census-designated places are geographical areas designated by the US Census Bureau for the purpose of compiling demographic data. They are not actual jurisdictions under Pennsylvania law. Other unincorporated communities are listed here as well.

The population ranking of the following table is based on the 2010 census of Mifflin County.^[16]

† county seat