Czechoslovak State Railways (Československé státní dráhy in Czech or Československé štátne dráhy[a] in Slovak, often abbreviated to ČSD) was the state-owned railway company of Czechoslovakia.

It took over the rolling stock and infrastructure of the Imperial Royal Austrian State Railways.

Of these 81% were state (ČSD)-owned, and the trend was to nationalize the remaining private railways.

When Nazi Germany dissolved Czechoslovakia in 1939, the Protectorate of Bohemia and Moravia formed the "Bohemian-Moravian Railway" company (in Czech Českomoravské dráhy-ČMD, in German Böhmisch-Mährische Bahn-BMB) under the control of Deutsche Reichsbahn (DR).

The fixed infrastructure was transferred to the successor countries according to location; the remainder was divided by 2:1 ratio.