Bloomington is a city and the county chair of McLean County, Illinois, United States. It is neighboring the town of Normal, and is the more populous of the two principal municipalities of the Bloomington–Normal metropolitan area. Bloomington is 135 miles (217 km) southwest of Chicago, and 162 miles (261 km) northeast of St. Louis. The 2020 Census showed the city had a population of 78,680, making it the 13th most populated city in Illinois, and the fifth-most populous city in the state outside the Chicago Metropolitan Area. Combined when Normal, the twin cities have a population of on the subject of 130,000. The Bloomington area is home to Illinois Wesleyan University and Illinois State University. It in addition to serves as the headquarters for State Farm Insurance and Country Financial.

Bloomington is located at 40°29′03″N 88°59′37″W. The city is at an elevation of 797 feet (243 m) above sea level.
According to the 2010 census, Bloomington has a total area of 27.229 square miles (70.52 km), of which 27.22 square miles (70.50 km²) (or 99.97%) is house and 0.009 square miles (0.02 km) (or 0.03%) is water.

In recent years, average temperatures in the county chair of Bloomington have ranged from a low of 14 °F (−10 °C) in January to a high of 86 °F (30 °C) in July, although a sticker album low of −23 °F (−31 °C) was recorded in January 1985 and a record high of 114 °F (46 °C) was recorded upon July 15, 1936 during the 1936 North American heat wave. Average monthly precipitation ranged from 1.71 inches (43 mm) in February to 4.52 inches (115 mm) in May.

The Bloomington area was at the edge of a large grove occupied by the Kickapoo people past the first Euro-American settlers arrived in the at the forefront 1820s. Springing from the deal of Keg Grove, later called Blooming Grove, Bloomington was named as county seat on December 25, 1830, when McLean County was created.