The community was named for the fact a large share of the first settlers were farmers. The area was first settled by James Goodin in the late 1700s, by Nicholas Wood and family, and by Jacob Straight and family in the 1770s. A later settler, Joseph Morgan, would build a mill here in 1801. The area would later be incorporated in Marion County as the town of Farmington in 1896, but was earlier known as Willeyvile, Willeytown, and Underwood. While it was officially named Farmington in 1896, when the Baltimore and Ohio Railroad ran through the town its stations there went under the name Underwood because of there being many towns of the same name. The town was also home to mines Number 08 of Jamison Coal and Coke Company (exploded in 1926 and then sealed in the 1940s) and Number 09 of Consolidated Coal Company (exploded in 1954 and 1968, then sealed in 1978), to the Farmington High School "Farmers" and the North Marion High School Huskies, and to several small family businesses that run to present day.