Rock Island is a medium-sized city located in the state of Illinois. With a population of 36,256 people and 12 associated neighborhoods, Rock Island is the 50th largest community in Illinois.

The population of Rock Island overall has a level of education that is slightly above the US average for all US cities and towns of 21.84%. Of adults 25 and older in Rock Island, 22.53% have at least a bachelor's degree.

The per capita income in Rock Island in 2018 was $30,235, which is lower middle income relative to Illinois, and middle income relative to the rest of the US. This equates to an annual income of $120,940 for a family of four. However, Rock Island contains both very wealthy and poor people as well.

Rock Island is an extremely ethnically-diverse city. The people who call Rock Island home describe themselves as belonging to a variety of racial and ethnic groups. The greatest number of Rock Island residents report their race to be White, followed by Black or African-American. Rock Island also has a sizeable Hispanic population (people of Hispanic origin can be of any race). People of Hispanic or Latino origin account for 13.63% of the city’s residents. Important ancestries of people in Rock Island include German, Irish, English, Swedish, and Belgian.

The most common language spoken in Rock Island is English. Other important languages spoken here include Spanish and African languages.