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. It is part of the Morgan City Micropolitan Statistical Area.
Franklin, named for Benjamin Franklin, was founded in 1808 as Carlin's Settlement by French-born pioneer Joseph Carlin and his family. It became the parish seat in 1811 and the town was incorporated in 1820. Though early settlers included French, Acadian, German, Danish and Irish, the town's culture and architecture is heavily influenced by the unusually large numbers of English that chose to settle there after the Louisiana Purchase in 1803. Numerous large sugar plantations arose in the area, and with the development of steamboating, Franklin became an interior sugar port. Franklin's First United Methodist Church was established in 1806, making it the first Protestant church established in the state of Louisiana.
By the 1830s, Bayou Teche was the main street of Acadiana, with one plantation after another.