Union der Bergarbeiter in der CSR ('Union of Miners in the Czechoslovak Republic'), initially known as Union der Bergarbeiter Österreichs ('Union of Miners of Austria'), was a miners trade union of miners in Austria and the First Czechoslovak Republic 1903-1938. Initially a multi-ethnic union in Habsburg Austria (Cisleithania), it was divided along ethnic lines in 1910. After the establishment of the Czechoslovak Republic, it became a union for miners of German ethnicity.