Blue Island is a city in Cook County, Illinois, United States. The population was 23,706 at the 2010 census.
Blue Island was established in the 1830s as a way station for settlers traveling on the Vincennes Trace, and the settlement prospered because it was conveniently situated a day's journey outside of Chicago. The late nineteenth century historian and publisher Alfred T. Andreas made the following observation regarding the physical appearance of the nascent community in his History of Cook County Illinois (1884), which must have played at least a part in its ability to attract settlers in the early years: "The location of Blue Island Village is a beautiful one. Nowhere about Chicago is there to be found a more pleasant and desirable resident locality."
Since its founding, the city has been an important commercial center in the south Cook County region, although its position in that respect has been eclipsed in recent years as other significant population centers developed around it and the region's commercial resources became spread over a wider area. In addition to its broad long-standing industrial base, the city enjoyed notable growth in the 1840s during the construction of the feeder canal (now the Calumet Sag Channel) for the Illinois and Michigan Canal, as the center of a large brick-making industry beginning in the 1850s (Blue Island was at one time considered to be the brick-making capitol of the world), and, beginning in 1883, as host to the car shops of the Rock Island Railroad. Until the Eighteenth Amendment put them out of business in 1919, Blue Island was home to several breweries who used the east side of the hill to store their product before the advent of refrigeration. A large regional hospital and two major clinics are located in the city.
Although initially settled by "Yankee" stock, Blue Island has been the point of entry for many of America's immigrants, beginning in the 1840s with the arrival of a large German population that remained a prominent part of the city's ethnic makeup for many years. Indeed, by 1850 fully half of Blue Island's population was either foreign-born or the children of foreign-born residents. Later, significant groups came from Italy, Poland, Sweden and Mexico.