Southbury is a town located in western New Haven County, Connecticut, United States north of Oxford and Newtown and east of Brookfield. The population was 18,567 at the 2000 census. Southbury comprises rural country areas, suburban neighborhoods, and historic districts. It is located a short distance from major business and commercial centers and is within 100 miles (160 km) of New York City and 150 miles (240 km) of Boston. Southbury is the only town in the country with the name 'Southbury', which may be why the town seal reads "Unica Unaque," meaning "The One and Only."