Westfield is a town in Orleans County, Vermont in the United States. The population was 503 at the 2000 census. It is the least densely populated (most rural) town in the county. The town was founded in 1780 and named after Rhode Island general and politician, William West, a supporter of Vermont statehood. Westfield is home to the Monastery of the Immaculate Heart of Mary, a contemplative order of women, following the Benedictine rule.