The Great Brak River is a river in the Western Cape, South Africa. The mouth of the river lies at the town of Great Brak River which falls under the Mossel Bay Municipality. The nearest large towns are Mossel Bay, 24 km to the west, and George, 34 km to the east by road.
The main tributaries of the Great Brak are the Perdeberg River, Tweeriviere River and Varings River. The Wolwedans Dam is the only dam in the river.