Bahr el Ghazal: The Bahr el Ghazal region in northwest South Sudan includes the states of:
1.Northern Bahr el Ghazal
2.Western Bahr el Ghazal
According to the disputed 2008 census conducted under the Republic of the Sudan,Western Bahr al Ghazal is the least populous of South Sudan's states.
Equatoria: The Equatoria region in southern South Sudan includes the states of:
The state capital of Central Equatoria, the smallest South Sudanese state by area, is Juba, which also serves as the national capital of South Sudan.
Greater Upper : NileThe Greater Upper Nile region in northern and eastern South Sudan includes the states of:
Jonglei is the largest state of South Sudan by area, as well as the most populous, according to the 2008 census.