West Monroe is a city in Ouachita Parish, Louisiana, United States. The population was 13,250 at the 2000 census. It is part of the Monroe Metropolitan Statistical Area. West Monroe is situated on the Ouachita River, just across from the neighboring city of Monroe (pop. 53,107). The two cities are often referred to as the Twin Cities of northeast Louisiana. It was originally named Trenton. Recently there has been an aborning interest in renaming the city Trenton.