 According to the United States Census Bureau, the township has a total area of 23.7 square miles (61.4 km²), all of it land.Westfield Township is bordered by Brookfield Township to the north, Deerfield and Chatham Townships to the east, Clymer Township to the south and Harrison and Hector Townships in Potter County to the west.As of the census of 2000, there were 849 people, 338 households, and 267 families residing in the township.