The first settlers to the Town of Thompson in 1749 were farmers David Gray and Z. Hatch, who put down roots in the vicinity of Dutch Pond.
The Town of Thompson was named after William A. Thompson, a native of Litchfield County, Connecticut. He was a miller who arrived in the area in 1794. Thompson bought land and built a settlement near what was then known as Albion. Thompson, who later became a judge, and his family are buried in a historical cemetery behind the present
Thompsonville Post Office.
Thompson, taken from the Town of Mamakating, was formed by an act of the State Legislature in April 1803. The Village of Monticello was incorporated in 1830. The first town meeting of Thompson was held at the house of Abraham Warring, who kept a tavern in Thompsonville.