The Habsburg Law was a law originally passed by the Constitutional Assembly of the Republic of German-Austria, one of the successor states of dissolved Austria-Hungary, on 3 April 1919. The law dethroned the House of Habsburg-Lorraine as rulers of the country, which had declared itself a republic on 12 November 1918, exiled them and confiscated their property. The Habsburg Law was repealed in 1935 and the Habsburg family was given back its property. However, in 1938, following the Anschluss, the Nazis reintroduced the Habsburg Law, and it was retained when Austria regained its independence after World War II.

The Republic of German-Austria was an unrecognised state that was created following World War I as an initial rump state for areas with a predominantly German-speaking and ethnic German population within what had been the Austro-Hungarian Empire, with plans for eventual unification with Germany. The territories covered an area of 118,311 km2 (45,680 sq mi), with 10.4 million inhabitants.