[5] Incorporated in 1833 and designated a city in 1886, Middletown was formed from parts of Lemon, Turtlecreek, and Franklin townships.

[6] The city also features Hook Field Municipal Airport, now serving only general aviation, and a regional campus of Miami University.

[9] Stephen Vail Jr. purchased land on the eastern bank of the Great Miami River from Symmes and platted 52 lots for the village in 1802.

[12] Middletown was principally known for its agriculture and paper mills but became most famous as a steel town when George Verity, founder of American Rolling Mill Company (ARMCO) opened a sheet steel rolling process plant in 1900.

[12] The city's name is believed to have been given by its founder, Stephen Vail, but questions remain unanswered as to why.

One local historian stated that the city received its name because Vail had come from Middletown, New Jersey.

[13][14] Vail centered the city in Fractional Section 28 of Town 2, Range 4 North.

One of the first settlers in Middletown was Daniel Doty, who migrated there from New Jersey in the late 18th century.

Middletown also borders the cities of Franklin, Monroe, Trenton, and Liberty and Madison Townships.

85% of residents were high school graduates, and 15.6% had received bachelor's degrees or higher.

[21] Miami University, based in Oxford, Ohio, has a regional campus in Middletown.

Ohio State Route 122 accesses Interstate 75 running to the east of Middletown.

[25] Transit service was formerly provided by the privately owned Ortman-Stewart Transportation Company, which ceased operations at the end of 1972.

[26] Today, the Butler County Regional Transit Authority provides bus service in the city with connections to Hamilton, Oxford, as well as Springdale, where riders can transfer to the Southwest Ohio Regional Transit Authority serving greater Cincinnati.

[26] Vice President JD Vance describes his life in Middletown in Hillbilly Elegy: A Memoir of a Family and Culture in Crisis (2016).

His family had moved there from Jackson, Kentucky, and became caught in the problems of industrial restructuring and loss of jobs.