Mont Tournier, Mountain summit in Savoie, France

Mont Tournier is a mountain ridge in the Avant-Pays savoyard, Savoie, reaching 877 m at its highest point. It runs about 20 km from Yenne in the north to La Bridoire in the south, 1 to 4 km wide, with several lesser summits along the crest: Montmerle (631 m), Montbel (706 m) and Mont Chaffaron (854 m). Its upper part is a band of pale limestone cliffs above wooded slopes, with a grassy field in the foreground.

Mont Tournier is an anticline of Lower Cretaceous limestone, eroded since the Pliocene and considered, with the Chaîne de l'Épine, the southern end of the Jura massif. Its southern half joined the Parc naturel régional de Chartreuse on 20 October 2022, when communes around Lac d'Aiguebelette entered the protected area. The whole ridge is a type II ZNIEFF.

The mountain's southern cliffs above Verel-de-Montbel are said to have sheltered the smuggler Louis Mandrin in caves. Local tradition links this limestone edge, which drops from about 600 to 300 metres toward the lac d'Aiguebelette, to his contraband routes.

The ridge runs about 20 km from Yenne in the north to La Bridoire in the south, only 1 to 4 km wide, and its northern half is the harder to cross. Small roads cross it in the south over the cols du Mont Tournier, de la Lattaz, de la Crusille and du Banchet; the A43 passes through the Dullin tunnel in the southern cliffs.

The cliffs above Verel-de-Montbel, on the southern part of the ridge, are said to have sheltered the smuggler Louis Mandrin in caves. The limestone anticline here continues south of La Bridoire as the Ratz anticline, offset by a fault.