West Carthage is a village in Jefferson County, New York, United States.

Settlement began circa 1798 with a ferry service and tavern established at that location, but development was slower compared to Carthage on the other side of the Black River in spite of water power available to both communities.

West Carthage is located in eastern Jefferson County at 43°58′25″N 75°37′17″W / 43.973678°N 75.621355°W / 43.973678; -75.621355,[6] in the town of Champion.

Its northeastern boundary follows the Black River, across which is the village of Carthage in the town of Wilna.

28.7% of all households were made up of individuals, and 15.9% had someone living alone who was 65 years of age or older.