Dorchester is a community in Westmorland County, New Brunswick, Canada. The community became part of the new town of Tantramar in the 2023 New Brunswick local governance reform. Originally incorporated as a town in 1911, it was converted to a village in 1966. By 1825 it had been named for Guy Carleton, 1st Baron Dorchester, an 18th-century Gov…Dorchester is a community in Westmorland County, New Brunswick, Canada. The community became part of the new town of Tantramar in the 2023 New Brunswick local governance reform. Originally incorporated as a town in 1911, it was converted to a village in 1966. By 1825 it had been named for Guy Carleton, 1st Baron Dorchester, an 18th-century Governor-General of the old Province of Quebec, but prior to that was called Botsford.