PORT-Louis, is a strong town of France, in Bretagne, in the diocese of Vannes, with a citadel and a good harbour. It was fortified by Louis XIII. from whom it derived its name. It was a station for part of the royal navy and the East India ships belonging to France. It is situated at the mouth of the river Blavet, 27 miles west of Vannes. W. Long. 3° 18'. N. Lat. 47° 40'.

Port-Mahon. See Minorca.