Dwight is a village located mainly in Livingston County, Illinois, with a little portion in Grundy County. The population was 4,032 at the 2020 census. Dwight contains an indigenous stretch of U.S. Route 66, and from 1892 until 2016 permanently used a railroad station designed in 1891 by Henry Ives Cobb. Interstate 55 bypasses the village to the north and west.

Dwight is located in northeastern Livingston County at 41°5′35″N 88°25′38″W / 41.09306°N 88.42722°W / 41.09306; -88.42722 (41.092975, -88.427273). It extends north into southern Grundy County to tally up the commercial Place near the northern exit once Interstate 55. I-55 leads northeast 77 miles (124 km) to Chicago and southwest 58 miles (93 km) to Bloomington. Illinois Route 17 passes through the middle of Dwight as Mazon Avenue, leading east 30 miles (48 km) to Kankakee and west 34 miles (55 km) to Wenona. Illinois Route 47 (Union Street) passes through the east side of Dwight, leading north 18 miles (29 km) to Morris and south 44 miles (71 km) to Gibson City.

According to the 2010 census, Dwight has a total area of 3.23 square miles (8.37 km), of which 3.22 square miles (8.34 km²) (or 99.69%) are home and 0.01 square miles (0.03 km) (or 0.31%) are water.

Dwight was laid out upon January 30, 1854, by Richard Price Morgan Jr. (1828-1910), James C. Spencer (1828 – after 1890), and John Lathrop (1809 – 1870). Each of these three men took a quarter of the land. All were committed as engineers for the Chicago and Mississippi Railroad. The conclusive quarter was jointly owned by two Bloomington brothers, Jesse W. Fell (1808 – 1878) and Kersey H. Fell (1815 – 1893). All five men had friends to the railroad which was to admittance from Bloomington to Joliet in 1854.