New Haven is a village in Gallatin County, Illinois, United States, along the Little Wabash River near its mouth at the Wabash River. The population was 399 at the 2020 United States Census, down from 433 at the 2010 United States Census.

Gallatin County is a county located in the U.S. state of Illinois. According to the 2020 census, it has a population of 4,946, making it the third-least populous county in Illinois. Its county seat is Shawneetown. It is located in the southern portion of Illinois known locally as Little Egypt. Located at the mouth of the Wabash River, Gallatin County, along with neighboring Posey County, Indiana, and Union County, Kentucky form the tri-point of the Illinois-Indiana-Kentucky Tri-State Area.