Fairbury is a city in Livingston County, Illinois, United States. The population was 3,633 at the 2020 census. Fairbury is located on U.S. Route 24 11 miles east of Chenoa and six miles west of Forrest. It was founded in 1857. The town has a large population of members of the Apostolic Christian faith, who first settled in the area in 1864.