ST JEAN-DE-LUZ, a coast town of south-western France, in the department of Basses-Pyrénées, at the mouth of the Nivelle, 14 m. S.W. of Bayonne on a branch of the Southern railway. Pop. (1906) 3424. St Jean-de-Luz is situated in the Basque country on thebay of St Jean-de-Luz, the entrance to which is protected by breakwaters and moles. It has a 13th-century church, the chief features of which are the galleries in the nave, which, according to the Basque custom, are reserved for men. The Maison Lohobiague, the Maison de l'Infante (both 17th cent.), and the hôtel de ville (1657) are picturesque old buildings. St Jean is well known for its bathing and as a winter resort. Fishing is a considerable industry.
From the 14th to the 17th century St Jean-de-Luz enjoyed a prosperity due to its mariners and fishermen. Its vessels were the first to set out for Newfoundland in 1520. In 1558, owing to the depredations of its privateers, the Spaniards attacked and burned the town. In 1627, however, it was able to equip 80 vessels, which succeeded in saving the island of Ré from the duke of Buckingham. In 1660 the treaty of the Pyrenees was signed at St Jean-de-Luz, and was followed by the marriage there of the lnfanta Maria Theresa and Louis XIV. At that time the population numbered 15,000. The cession of Newfoundland to England in 1713, the loss of Canada, and the silting-up of the harbour were the three causes which contributed to the decline of the town.