West Jefferson is a village in Madison County, Ohio, United States. The population was 4,137 at the 2020 census. Located along U.S. Route 40, the village has a fairly close relationship with the surrounding township, which include various out-of-corporation-limit neighborhoods.

Madison County is a county located in the central portion of the U.S. state of Ohio. As of the 2020 census, the population was 43,824. Its county seat is London. The county is named for James Madison, President of the United States and was established on March 1, 1810.