Illinois Institute of Technology (IIT) is a private Ph.D.-granting university with programs in engineering, science, psychology, architecture, business, design and law. It was founded in 1940 by the merger of the Armour Institute of Technology (founded in 1893) and Lewis Institute (founded in 1895). (The IIT acronym sometimes causes it to be confused with ITT Technical Institute, an unrelated educational institution with a presence in the Chicago area.)

Several other colleges have since merged with IIT, including the Chicago-Kent College of Law, the Stuart Graduate School of Business, and the Institute of Design. Campuses are located in Bronzeville on the South Side of Chicago, at two locations in the Chicago Loop, and in suburban Wheaton Illinois. It has a student population of around 6,000: 1,800 undergrads, 3,000 graduate students, and 1,200 law students.

Architect Ludwig Mies van der Rohe designed many of the main campus buildings. In 1976, the American Institute of Architects recognized the campus as one of the 200 most significant works of architecture in the U.S. A new student center designed by Rem Koolhaas and a new state-of-the-art dormitory designed by Helmut Jahn opened in 2003, the first new buildings built on the main campus in 32 years, partly due to the difficulty entailed in adding on to an architecturally significant campus without detracting from the campus's character.

IIT's predecessor institution, Armour Institute, was founded by Philip Danforth Armour, a prominent Chicago meat packer and grain merchant, after he heard Chicago minister Frank Gunsaulus say that with a million dollars, he would build a school that would be open to students of all backgrounds, instead of just the elite as was common then. Gunsaulus became the first president.