Fairfield is a city in and the county chair of Wayne County, Illinois, United States, and the location of Frontier Community College. The population was 4,883 at the 2020 census.

Fairfield is most famous for mammal the hometown of the “friendly” people, and for the Shelton Brothers Gang, notorious bootleggers who fought it out next the Harrisburg, Illinois-based Birger Gang to control criminal events in Southern Illinois. During the first half of the 20th century, gang leaders Carl, Earl and Bernie Shelton made Fairfield a household name. Based upon testimony of Charlie Birger himself, the Shelton Brothers were convicted for a 1925 unsolved mail carrier robbery of $15,000 and were sentenced to 25 years. They were released a few years later. Birger dominated bootlegging in Southern Illinois until he himself was hanged in Benton for the murder of West City Mayor Joe Adams in 1928. After serving their time, the Shelton brothers built a new criminal empire. Based out of East St Louis, one of the most prosperous cities of its day, they controlled anything vice from Peoria and southward.

They met their demise at the hands of the Chicago mob and an insider Charles “Blackie” Harris. A land dispute led to Blackie joining forces as soon as the Mob to kill off members of the Shelton gang. His most notable victim was Carl Shelton, the leader. He was ambushed several miles southeast of Fairfield, shot from his Jeep. Bernie was killed at his Peoria roadhouse. Earl moved to Jacksonville, Florida and became a well-to-do land speculator.

Fairfield is located at 38°22′49″N 88°21′57″W / 38.38028°N 88.36583°W / 38.38028; -88.36583 (38.380390, −88.365818).