Saint-Jean-de-Maurienne (French pronunciation: [sɛ̃ ʒɑ̃ də mɔʁjɛn] ^ⓘ; Arpitan: Sent-Jian-de-Môrièna or Sant-Jian-de-Môrièna; Italian: San Giovanni di Moriana) is a subprefecture of the Savoie department, in the region of Auvergne-Rhône-Alpes (formerly Rhône-Alpes), in southeastern France.

It lies in the Maurienne, the valley of the river Arc. It was also an Episcopal See of Savoy during the Ancien Régime and again from 1825 to 1966. Its original name was simply Maurienne, or Moriana in Italian and Latin.

Saint-Jean-de-Maurienne is located at the confluence of the Arc, a river which has shaped the Maurienne Valley, and the Arvan [fr] which descends the Arves Valley (Col de la Croix de Fer).

The neighbouring communes of Saint-Jean-de-Maurienne are Saint-Julien-Mont-Denis, Jarrier, Hermillon, Villargondran, Albiez-le-Jeune, Albiez-Montrond, Saint-Pancrace and Pontamafrey-Montpascal.

Saint-Jean-de-Maurienne is close to Albertville (59 km), Chambery (72 km), Grenoble (103 km), Turin (137 km) and Lyon (174 km).

The climate is the alpine type because of the presence of the Alpine Massif.

Saint-Jean-de-Maurienne is on the route of the future Lyon-Turin rail link. Homes, businesses, the current railway station and the rescue centre are affected by the project. The Lyon Turin Railway company (LTF) which manages the construction projects plans to build new railway station in the Sous-le-Bourg neighborhood, serving both the historic line and the new Lyon-Turin line. Geological and topographical investigations are underway. The project promises to be even more complex than that of the Channel Tunnel.

The town of Saint-Jean-de-Maurienne is equipped with a network of public transport run by the Communauté de communes Cœur de Maurienne [fr].