The Serbian Free Corps (German: Serbische Freikorps), known simply as frajkori (Serbian Cyrillic: фрајкори), was a volunteer militia composed of ethnic Serbs, established by the Habsburg monarchy, to fight the Ottoman Empire during the Austro-Turkish War (1787–1791).

The rebellion in the Sanjak of Smederevo and militia's operations resulted in the period of Habsburg-occupied Serbia, which took place from 1788 to 1791.

[6] The Austrians used the Corps in two failed attempts to seize Belgrade, in late 1787 and early 1788.

[7] In 1793, the Austrians established the new free corps on the border, for Serbians and Bosnians.

[7] On the eve of the First Serbian Uprising, the Užice and Sokol nahije established volunteer detachments, called frajkori, that had the task of sabotage against Ottoman military plans, and their concentration in this region of Serbia.