Flemington is a borough in Hunterdon County, New Jersey, United States. As of the 2010 United States Census, the borough's population was 4,581, reflecting an increase of 381 (+9.1%) from the 4,200 counted in the 2000 Census, which had in turn increased by 153 (+3.8%) from the 4,047 counted in the 1990 Census. It is the county seat of Hunterdon County. Most of the borough is in the Amwell Valley (a low-lying area of the Newark Basin), but northwest portions of the borough sit on the Hunterdon Plateau.
Flemington is an independent municipality located entirely within (and completely surrounded by) Raritan Township and is located near the geographic center of the township.
Before European settlement, the land that comprises Flemington, as was all of Hunterdon County, was the territory of the Lenni Lenape Native Americans. In 1712, as part of a land parcel of , the Flemington area was acquired by William Penn and Daniel Coxe.
The surrounding fertile farmland dictated that the beginnings of Flemington were agricultural. Early German and English settlers engaged in industries dependent on farm products. As time passed poultry and dairy farms superseded crops in agricultural importance. An example of early settlement families was Johann David and Anna Maria Ephland, who emigrated in 1709 from Germany through London to New York and settled on his farm in 1717. They raised their seven children, and two from his previous marriage, on the farm that now makes up the core of Flemington.
In 1785, Flemington was chosen as the County Seat of Hunterdon. Fire destroyed the old courthouse in 1826 and the City of Lambertville made an ultimately unsuccessful attempt to have the seat relocated there. Flemington remained the County Seat and the Courthouse which stands today on Main Street was built.
What is now Flemington was originally formed as a town by an Act of the New Jersey Legislature on March 14, 1870, within portions of Raritan Township. It became a village as of June 11, 1894, still within Raritan Township. Flemington was finally incorporated as an independent borough by an Act of the New Jersey Legislature on April 7, 1910, based on the results of a referendum held on April 26, 1910, and was formally separated from Raritan Township. The borough's incorporation was confirmed on April 27, 1931.
In 1856, the Hunterdon County Agricultural society purchased of land that would accommodate the people, exhibits and livestock for the County (Flemington) Fair. The purpose of this Fair was to promote competition between farmers, stock raisers and machinery manufacturers. The fair was held every year at the Flemington Fairgrounds which also was the site of Flemington Fair Speedway (later Flemington Raceway). From 1992 through 1995, the speedway hosted the Race of Champions, a race for modified racers. The speedway hosted a NASCAR Craftsman Truck Series race from 1995 to 1998. In 2003, the County Fair adopted a new name, The Hunterdon County 4-H and Agricultural Fair, and moved to the South County Park in East Amwell Township.