The county is within a 200-mile (320 km) radius of major population centers, including Chicago, Cincinnati, Cleveland, Columbus, Detroit, Indianapolis, Louisville, Milwaukee, and within a one-day drive of one-third of the U.S. population and one-fifth of Canadians.

The county is named for Colonel John Allen, an attorney and Kentucky state senator who was killed in the War of 1812.

[4] Fort Wayne, founded at the confluences of the Maumee, St. Joseph, and St. Marys rivers, was chosen as the county seat in May 1824.

[13] Fort Wayne is cited as having the highest Burmese refugee population in the United States, with between 3,000 and 3,500.

The commissioners are charged with enacting and executing legislation, the collection of revenue, and managing the day-to-day functions of the county government.

Allen Superior Court hears the vast majority of cases, and has several divisions with multiple courtrooms.

Each of these elected officers serves a term of four years and oversees a different part of county government.

[18] The county government operates the jail, maintains rural roads, operates the major local courts, keeps files of deeds and mortgages, maintains vital records, administers public health regulations, and participates with the state in the provision of welfare and other social services.

Allen County is part of Indiana's 3rd congressional district and is represented by Jim Banks in the United States Congress.

[23][24] The last Democratic Governor to win the county was Frank O'Bannon in 2000 and the last Senator was Evan Bayh during his 2004 landslide.

[27] (information as of January 2024) The Allen County Courthouse was designed by Brentwood S. Tolan of Fort Wayne, and was built by James Stewart and Company of Saint Louis, Missouri.

The building is now used primarily as a government annex, as most of the offices were moved across Main Street to the Edwin J. Rousseau Centre in 1971.

However, Allen County's economy has diversified with time to include defense and security, healthcare, and insurance.

[33] Allen County is home of Purdue Fort Wayne (PFW), with an enrollment of 14,192, it is the fifth-largest public university campus in Indiana.

The entire library system began an $84.1 million overhaul of its branches in 2002, finishing work by 2007.

[36] The centerpiece, the Main Library Branch, now covers 367,000 square feet (34,100 m2), featuring an art gallery, underground parking garage, bookstore, café, and community auditorium.

[38] The Fred J. Reynolds Historical Genealogy Department, located in the Main Library Branch, is the largest public genealogy department in the United States, home to more than 350,000 printed volumes and 513,000 items of microfilm and microfiche.

Activities at various parks include hiking, swimming, fishing, sledding, cross-country skiing (rentals available), playgrounds, picnic areas, play fields, and many nature-based programs for all ages.