Alstom is a French multinational rolling stock manufacturer which operates worldwide in rail transport markets. It is active in the fields of passenger transportation, signaling, and locomotives, producing high-speed, suburban, regional and urban trains along with trams.

Alstom is its own manufacturer; it is a French multinational rolling stock manufacturer that operates in the rail transport markets worldwide. In 2021, Alstom significantly expanded its capabilities by acquiring Bombardier Transportation, making it the second-largest rail company in the world after China's CRRC. Today, in 2026, Alstom designs and manufactures some of the world's most famous train sets, including the TGV (Train à Grande Vitesse) in France and the Avelia Liberty (the new Acela) for Amtrak in the United States. They are also the pioneers behind the Coradia iLint, the world’s first passenger train powered by a hydrogen fuel cell. Alstom operates numerous production sites across the globe, with major facilities in France, Germany, India, and the United States. When you see an "Alstom" train, it is a product of over a century of French engineering heritage, now integrated with the global expertise inherited from the Bombardier acquisition, focusing heavily on "green" rail solutions and autonomous signaling systems.