West Montagu is a rural locality in the local government area (LGA) of Circular Head in the North-west and west LGA region of Tasmania. The locality is about north-west of the town of Smithton. The 2016 census recorded a population of 45 for the state suburb of West Montagu.
West Montagu was gazetted as a locality in 1973.
The waters of Robbins Passage, an inlet of Bass Strait, form the northern boundary, and the Montagu River forms the eastern.
Route C215 (Montagu Road) runs through from east to west.