Col de la Croix de Fer, Mountain pass in Saint-Sorlin-d'Arves, France.

Col de la Croix de Fer is a mountain pass at 2,065 metres on the boundary between the Grandes Rousses and Arves massifs, in the commune of Saint-Sorlin-d'Arves, Savoie. The D926 road crosses it, linking the Maurienne valley with the Romanche valley via Saint-Jean-de-Maurienne and Le Bourg-d'Oisans, close to the Col du Glandon. A black iron cross with rounded, circled arm ends stands on a stone shaft above a stepped base of rough grey stones.

The pass was first crossed by the Tour de France in 1947, when Fermo Camellini led over the summit. It has featured 22 times since, was classified first category until 1986 and hors catégorie from 1989. The mule track over the col became a road in 1900 from Saint-Sorlin-d'Arves, extended to the Col du Glandon on 14 July 1912.

The name refers to the Iron Cross, a metal cross standing at the summit that serves as a landmark for cyclists and hikers crossing this route. The cross has become a symbol of achievement for those who reach the top.

The D926 is open to traffic from June to October. From Rochetaillée the road forks 2.5 km before the summit, one branch leading to the Col du Glandon. The northeast climb from Saint-Jean-de-Maurienne passes through four tunnels.

The pass lies on the boundary between the Grandes Rousses and Arves massifs, where the Croix-de-Fer volcano-sedimentary complex outcrops: layered dacitic breccias and tuffs topped by two acidic andesitic flows and a final acidic flow. On the slopes, rounded rocks polished by a former glacier can still be seen.