Chicago is considered the most gang-occupied city in the United States, with 150,000 gang-affiliated denizens, representing more than 100 gangs. Gang warfare and retaliation is common in Chicago. Gangs were responsible for 61% of the homicides in Chicago in 2011.

Crime in Chicago has been tracked by the Chicago Police Department's Bureau of Records since the beginning of the 20th century. The city's overall crime rate, especially the violent crime rate, is higher than the US average. Gangs in Chicago have a role in the city's crime rate. The number of homicides in Chicago hit a 25-year high in 2021.