WEBWebsite. www.brattleboro.org. Brattleboro ( / ˈbrætəlbʌroʊ / ), [4] originally Brattleborough, is a town in Windham County, Vermont, United States, located about 10 miles (16 km) north of the Massachusetts state line at the confluence of Vermont's West River and Connecticut. With a 2022 Census population of 12,106, [5] it is the most ...