Thomaston was originally part of the Farmington Proprietor's purchase in 1684 of the Mattatuck Plantation, the Thomaston area achieved independence in 1739, as the Northbury Parish. Northbury and Westbury united in 1780 to form Watertown. In 1795 Northbury again separated to become Plymouth, the Thomaston section was called Plymouth Hollow.
In 1813 a man named Seth Thomas came to the hollow to manufacture clocks. By 1856 Thomas was labeling his clocks with "Thomas Town." He helped route the Naugatuck railroad through Plymouth Hollow, linking us with the brass center at Waterbury.
On July 6, 1875 Thomas Town became Thomaston in memory of Seth Thomas and the separation from Plymouth was confirmed by the State Legislature.