Cicero is an incorporated town in Cook County, Illinois, United States. The population was 85,616 at the 2000 census. A 2003 Census estimate showed the population dipped to 83,029. Cicero is named for the town of Cicero, New York, which in turn was named for Marcus Tullius Cicero, the Roman orator.

Originally, Cicero occupied six times its current territory. However, weak political leadership and town services resulted in towns such as Oak Park, Illinois and Berwyn, Illinois voting to split off from Cicero, and other portions such as Austin were annexed into the city of Chicago

Al Capone built his criminal empire in Cicero before moving to Chicago. The town features in The Resistible Rise of Arturo Ui, a play by Bertolt Brecht which compares the Chicago gangsters and the rise to power of Adolf Hitler.

The 1980s and 1990s saw a heavy influx of Hispanic (mostly Mexican and Central American) residents to Cicero, displacing most other ethnicities. Once considered mainly a Czech or Bohemian town on Cermak Road (22nd Street), most of the European-style restaurants and shops have been replaced by Spanish-titled businesses. Cicero most recently is seeing a new influx of residents, mostly Puerto Rican and Polish American. Cicero also has seen a revival in its commercial sector, with many brand-new minimalls and large retail stores. New condos are also being built in Cicero, ranging in price from $150,000 to $300,000.

Cicero has long had a reputation of government scandal. Most recently, Town President Betty Loren-Maltese was sent to federal prison for misappropriating funds. She was well-liked by retired, long-term Cicero residents, but was continually challenged by younger Hispanic opponents before her indictment.

Cicero was taken up and abandoned several times as site for a civil rights march in the mid 1960s. The American Friends Service Committee, The Rev. Martin Luther King, and many affiliated organizations, including churches, were conducting marches against housing and school de facto segregation and inequality in Chicago and several suburbs, but the leaders feared too violent a response in Chicago Lawn and Cicero. Eventually, a substantial march (met by catcalls, flying bottles and bricks) was conducted in Chicago Lawn, but only a splinter group dared march in Cicero.