Franklin is a small city in and the parish seat of St. Mary Parish, Louisiana, United States. The population was 7,660 at the 2010 census. The city is located on Bayou Teche, southeast of the cities of Lafayette, 47 miles and New Iberia, 28 miles, and 22 miles northwest of Morgan City. It is part of the Morgan City Micropolitan Statistical Area and the larger Lafayette-Acadiana combined statistical area.