Middletown is an independent, home rule-class city in Jefferson County, Kentucky, United States, and a suburb of Louisville.

The City of Middletown was originally incorporated in 1797 by the Jefferson County Court on 500 acres of land lying on a branch of the forks of Beargrass Creek that originally belonged to Jacob Meyers and Culberth Harrison.

Though there is no recorded explanation why the city was named Middletown, it is commonly believed that that name was chosen because the town was in the "middle" of the two older cities of Louisville which was founded June 24, 1778, and Shelbyville, which was founded December 20, 1792.

In 1871 the Kentucky General Assembly amended the original charter to increase Middletown's boundaries.

After failing to hold elections and collect taxes after 1919, Circuit Judge Macauley Smith dissolved the city's charter on July 26, 1960, and Middletown lost its 163-year-old city status.

The racial makeup of the city was 87.1% White (85.1% non-Hispanic), 7.1% African American, 0.11% Native American or Alaska Native, 2.8% Asian, 0.07% Pacific Islander, 0.87% from other races, and 1.9% from two or more races.

35.4% of all households were made up of individuals, and 16.6% had someone living alone who was 65 years of age or older.

26.9% of all households were made up of individuals, and 9.5% had someone living alone who was 65 years of age or older.

Middletown is also home to a small 24 hour paid police department based out of city hall.