The Leaning Tower of Niles, Illinois, was completed in 1934 by industrialist Robert Ilg as part of a recreation park for employees of the Ilg Hot Air Electric Ventilating Company of Chicago. It is situated at 6300 W. Touhy Avenue and it is a 1/2 size copy of the original tower in Pisa, Italy, which is Niles' sister city.

Some speculate that part of the motivation to construct the tower was to celebrate the 600th anniversary of the Leaning Tower of Pisa. A more likely explanation is its original functional purpose, to store water for outdoor recreational swimming pools. In 1960, the descendants of Robert Ilg donated part of the park for the construction of the Leaning Tower YMCA. Other amenities of the employees' recreational park included a wooden toboggan run, which was in decay but still visible in the 1960s.

In 1991, the village of Niles, Illinois, established a sister city pact with Pisa, Italy. A US$1.2 million renovation of the Leaning Tower of Niles was started in 1995 by Mayor Nicholas Blase and the Board of Trustees, and was completed in 1996, improving the structure, facade and the Plaza area. The Leaning Tower Plaza area now has four fountains and a 30-foot pool. Village web site and publications include images of the tower. Leaning Tower Concert Series are Summertime open-air music concerts sponsored by the village since the 1990s.