West Monroe is a city in Ouachita Parish, Louisiana, United States. It is situated on the Ouachita River, across from the neighboring city of Monroe. The two cities are often referred to as the Twin Cities of northeast Louisiana. Its population was 13,065 at the 2010 census and it is part of the Monroe Metropolitan Statistical Area.

Ouachita Parish is located in the northern part of the U.S. state of Louisiana. As of the 2020 census, the population was 160,368. The parish seat is Monroe. The parish was formed in 1807.