The Kingdom of Serbs, Croats and Slovenes was formed in 1918 and was initially divided into counties and districts (this division was inherited from previous state administrations).

In 1929, the 33 oblasts were administratively replaced with 9 banovinas and one district, and the territory of the Bihać Oblast was incorporated into the new Vrbas Banovina.

The Bihać Oblast included western Bosanska Krajina.

According to the 1921 census, the Bihać Oblast was linguistically dominated by speakers of Serbo-Croatian.

[1] The main cities and towns located within the oblast were: All the mentioned cities and towns are now part of Bosnia and Herzegovina