Saint-Nazaire (săN-näzĕr´), city (1990 pop. 66,087), Loire-Atlantique dept., W France, at the mouth of the Loire River on the Bay of Biscay. Saint-Nazaire is an important seaport (mainly for trade with the Antilles and Central America) and a great shipbuilding and industrial center with aeronautical, metallurgical, chemical, and food industries. It is a port for the French navy. Built on the site of an ancient Gallo-Roman town, Saint-Nazaire belonged to the dukes of Brittany in the 14th and 15th cent. A major German submarine base during World War II, Saint-Nazaire was nearly destroyed by Allied bombing.