De Dietrich Ferroviaire (DDF) is a French manufacturer of railway rolling stock based in Reichshoffen, France. It was formed as a division of the De Dietrich group, which has a history going back to 1684. DDF constructed the carriages for the Enterprise train service jointly operated by Iarnród Éireann and Northern Ireland Railways between Dublin in the Republic of Ireland and Belfast in Northern Ireland. DDF were part of the consortium which constructed the rolling stock for the Eurostar service from London in the United Kingdom through the Channel Tunnel to Paris, France and Brussels, Belgium.

In the 1990s, a majority stake in DDF was acquired by Alstom and the company is now known as Alstom DDF.