Port-Louis is a commune in the Morbihan department of Brittany in north-western France. Inhabitants of Port-Louis are called in French Port-Louisiens.

At the beginning of the 17th century, merchants who were trading with India established warehouses in Port-Louis. They later built additional warehouses across the bay in 1628, at the location which became known as "L'Orient" (the Orient in French). In 1664, during the reign of King Louis XIV, the French East India Company was established at Port-Louis. The company established a shipyard at Lorient. The Company was not able to maintain itself financially, and it was abolished in 1769. In 1770, King Louis XVI issued an edict that required the Company to transfer to the state all its properties, in return for which the King agreed to pay all of the Company’s debts and obligations. The French government then took over the shipyards as a naval port and arsenal.