River Narnia (known locally amongst the Narnians as the Great River) was the central waterway through mainland of the Narnian kingdom, which existed since the dawn of time.

Beginning at the Garden of Youth in the Western Wild region, the river then falls down the Great Waterfall into the Cauldron Pool. The Great River then continues to flow through Lantern Waste, Beaversdam, and Beruna and its fords, ending at the Great River Delta, the location of Narnia's capital of Cair Paravel, which ultimately dispersed out into the Merepeople Nation by the Great Eastern Ocean.

Its tributaries included the River Archenland and the River Rush.