The LGV Sud-Est is a French high-speed rail line which connects the Paris and Lyon areas. It was France's first high-speed rail line. The inauguration of the first section between Saint-Florentin and Sathonay-Camp by President François Mitterrand on 22 September 1981 marked the beginning of the re-invigoration of French passenger rail service.

France has a large network of high-speed rail lines. As of June 2021, the French high-speed rail network comprises 2,800 km (1,740 mi) of tracks, making it one of the largest in Europe and the world. As of early 2023, new lines are being constructed or planned. The first French high-speed railway, the LGV Sud-Est, linking the suburbs of Paris and Lyon, opened in 1981 and was at that time the only high-speed rail line in Europe.