The Turin–Lyon line is a new high-speed, high-capacity railway line designed to connect the cities of Turin and Lyon across the Alps. The project forms an integral part of the Trans-European Transport Network (TEN-T), an infrastructure programme promoted by the European Union to make the movement of goods and people across the continent more efficient, interconnected and sustainable. Specifically, the line forms part of the Mediterranean Corridor, one of the nine strategic axes linking the Iberian Peninsula to Central and Eastern Europe.

The project extends along a route of 270 kilometres in total, of which approximately 70% is in France and the remaining 30% in Italy, and involves the excavation of 162 kilometres of tunnels. At the heart of the infrastructure is the Mont-Cenis Base Tunnel, a 57.5-kilometre-long tunnel which, once completed, will become the longest railway tunnel ever built internationally, linking Saint-Jean-de-Maurienne (Savoie, France) to Chiomonte (Piedmont, Italy). The Turin–Lyon project addresses several strategic objectives. Firstly, it aims to boost rail freight transport, currently hampered by the historic Frejus tunnel, in operation since 1871, which no longer meets the international standards required in terms of capacity, safety and gradient. The new line will enable over a million lorries a year to be shifted to rail, reducing freight transport costs across the Alps by 40% and contributing significantly to the decarbonisation of the logistics sector in the mountainous region. From a passenger perspective, the new infrastructure will significantly reduce journey times: the Turin–Lyon journey will drop from the current 4 hours to less than 2, whilst the Milan–Paris journey will fall to around 4 hours, compared to the current 6.

Once completed, the Turin–Lyon line will mark a turning point for European mobility, offering a faster, more efficient and sustainable alternative to road traffic along the western Alpine axis, improving connections between Italy, France and the rest of the continent.

Work on the base tunnel began in 2019 and the project is expected to be completed between 2032 and 2033. The total investment for the construction of the new Turin–Lyon railway line amounts to approximately €8,600,000,000.