Manu is a river in southeastern Peru. The Manu River runs down the eastern slopes of the Andes Mountains into the Amazon Basin. It runs through the Manu National Park, a vast Biosphere Reserve, home to arguably the highest concentration of biodiversity on Earth. Few live along its length. Much of the park is off-limits to all but permitted scientists and the indigenous groups of Amazonian Indians, mostly of the Machiguenga tribe. The Manu is a tributary to the Madre de Dios River.

In Hinduism, Manu (also Manu Vaivasvate) was a son of Saranya and either Surya or Vivasvat. Manu once caught a talking fish who begged him to rescue it. The fish claimed a Great Flood was coming and it would wash away all living things. Manu put the fish in a pot, and then, as it grew larger, into a tank, a lake and then the ocean. While in the ocean, the fish told Manu to build a boat. He did so and when the flood arrived, the fish (actually Matsya) towed the ship by a cable to attached to his horn.