Brahmani River is the second largest river that originated and flows through the state of Orissa in India. The river originates near the Nagri village, near the industrial town of Rourkela, in the district of Dhenkanal in Orissa at the confluence of the Shankha and South Koel rivers. The river originated at an elevation of about 600 m. The total length of the river is 799 km out of which, about 541 km lies in the state of Orissa. Brahmani River flows through the Eastern Ghats in the districts of Sundargarh, Kendujhar, Dhenkanal, Cuttack and Jajpur. It goes around the south and southeast, past the areas of Bonaigarh and Talcher and then turns towards the east to unite with the northern branches of the Mahanadi River. Together with the rivers Mahanadi and Baitarani, the river forms a large delta on the Orissa coastal plain before entering into the Bay of Bengal at Dharma.

Both the sources of the Brahmani River, the Shankha and South Koel rivers, have their origin in the state of Jharkhand. While the Shankha River has its origins near the Netarhat Plateau in Jharkhand-Chhattisgarh border, the South Koel has its origins in Jharkhand near Lohardaga. Both the sources of the Brahmani River are in the Chota Nagpur Plateau and the site of the river has mythological importance. It is the birth place of the compiler of the Mahabharata, Ved Vyasa. Hence, the place is called as Ved Vyasa at present.

Brahmani River has a total catchment area of over 39,033 sq km in Orissa. It has a few tributaries flowing throughout the state. Out of these tributaries, the Karo, the Sankh and the Tirka are the most notable ones. The Brahmani River and its tributaries play a major role in the entire irrigation system of the state of Orissa. There is a large dam namely the Rengali dam constructed on the Brahmani River near the town of Bonaigarh in Angul district in Orissa. As a consequence of the dam, a large reservoir with the same name was created near the location. The reservoir helps a lot irrigating the dry lands in the region. Apart from the Rengali dam, there is also a barrage constructed on the Brahmani River. The barrage is called as the Samal Barrage and is located near Talcher. The other major irrigation projects on the river include the Jokadia and the Jenapur anicuts. The Brahmani River is also crossed, near its mouth, by the Orissa Coast Canal that takes water from it.