 According to the United States Census Bureau, the township has a total area of , of which, of it is land and of it (0.20%) is water.Delmar Township is bordered by Chatham and Middlebury Townships to the north, Charleston Township to the east, Duncan Township to the south and east, Morris Township to the south, Elk Township to the west and Shippen Township to the north and west.Delmar Township forms the northern, western, and southern borders of the borough of Wellsboro.