Jonesville is the largest town in Catahoula Parish, Louisiana, United States, at the confluence of the Ouachita, Tensas, and Little rivers. The three rivers become the Black River at Jonesville. The Jonesville population was 2,265 at the 2010 census. The four rivers which intersect near Jonesville are all subject to flooding. There are surrounding soybean and cotton fields. A few plantation houses still stand, built during the former slavery-based, planter-dominated economy.