The town of Southbury was one of several towns formed out of a parcel of land purchased from the Paugussett Indians in 1659. It was originally part of Woodbury, as settled in 1673. A new meetinghouse, for the Southbury Ecclesiastical Society, was built in 1733, and in 1787 the town of Southbury was incorporated. Although incorporated as part of Litchfield County, Southbury has been in New Haven county for most of its existence.
In the 1800's, water power became essential to the growth of Southbury industries. These included mills, tanneries and distilleries. This water power came primarily from the Pomperaug and Housatonic rivers. As the industrial revolution progressed, many of these businesses left for Waterbury.