Fairbury is a city in Livingston County, Illinois, United States. The population was 3,633 at the 2020 census.

Francis Everett Townsend was an American physician and political activist in California. In 1933, he devised an old-age pension scheme to help alleviate the Great Depression. Known as the "Townsend Plan", this proposal would pay every person over age 60 $200 per month, with the requirement it all be spent quickly. It was never enacted but the popularity of the Plan influenced Congress to start the Social Security system, which involved much smaller amounts. The Plan was organized by real estate salesman Robert Clements, who made Townsend only a figurehead while the Plan expanded to thousands of clubs in many states. Townsend was born just outside Fairbury, Illinois, where he is memorialized by a post office named in his honor.