The Nantes Congress was the sixth national congress of the French Socialist Party (Parti socialiste or PS). It took place from June 17 to 18, 1977; right after the left's victory in the local elections.

At the Congress, the more moderate François Mitterrand comprehensively defeated the left wing challenger Jean-Pierre Chevènement.

François Mitterrand was re-elected as First Secretary.

Coordinates: 47°13′05″N 1°33′10″W / 47.2181°N 1.5528°W / 47.2181; -1.5528

Nantes (French pronunciation: [nɑ̃t]) (Breton: Naoned, Gallo: Naunnt) is a city in western France, located on the Loire River, 50 km (31 mi) from the Atlantic coast. The city is the 6th largest in France, while its metropolitan area ranks 8th with over 800,000 inhabitants.

Nantes is the capital city of the Pays de la Loire region and Loire-Atlantique département. Together with Vannes, Rennes and Carhaix, it was one of the major cities of the historic province of Brittany, and the ancient Duchy of Brittany. Culturally, Nantes is a Breton city.

In 2004, Time described Nantes as "the most liveable city in Europe". In 2010, Nantes was named a hub city for innovation in the Innovation Cities Index by innovation agency, 2thinknow. The city was ranked 36th globally from 289 cities and 4th overall in France, behind Paris, Lyon and Strasbourg for innovation across multiple sectors of the economy.

The name Nantes, pronounced [nɑ̃t] in French, derives from that of its pre-Roman-era inhabitants, the Gaulish tribe known as the Namnetes, who founded a town there around 70 BC. The city was called Portus Namnetum during the Roman occupation that began in 56 BC. The inhabitants of Nantes are known in French as Nantais ([nɑ̃tɛ]).