German Social Democratic Party in Czechoslovakia

The German Social Democratic Labor Party in Czechoslovakia (DSAP, "Deutsche sozialdemokratische Arbeiterpartei in der Tschechoslowakischen Republik"; "Německá sociálně demokratická strana dělnická v ČSR") was a Sudeten German social-democratic party in . The party was founded in 1919; its first leader was Josef Seliger.

In the first Czechoslovak republic, DSAP was the most important German party, which aimed at giving the German people a place in the republic. At first the party's leadership was politically and socially radical; the Czechoslovakian State was regarded as a "creation of Allies' Imperialism" and the Czechoslovakian Constitution as "suicide of democracy". However, these politics were shortly changed as the radical-left wing left the party (and joined the Czechoslovak Communist Party) in January 1921.

Some notable members of the party started talks with President Masaryk who - in vain - tried to persuade the party to join the government. It agreed finally in 1929, when its leader Ludwig Czech became Minister of Public Affairs.

During the years of the great economic crisis, the party lost many of its Sudeten German supporters, and the Sudeten German Party (SdP) gained importance. As after the Munich Agreement the troops of Nazi Germany began occupying the Sudetes areas (on 1 October 1938), only some of the anti-Nazi opposition members could retreat into remaining Czechoslovakian territories. Immediately after the entry of the Nazi troops, the persecution of the Social democrats and other opponents of Nazism began. From October to December 1938, 20,000 members of the Social Democratic Party were arrested; 2,500 Sudeten Germans were sent to the Dachau concentration camp alone. Around 30,000 people managed to flee to the West. On 22 February 1939 the DSAP leadership decided to stop all activities in the territory of the Czechoslovakian Republic and to continue working abroad as "Treuegemeinschaft sudetendeutscher Sozialdemokraten".