The Kon-Tiki expedition was a 1947 journey by raft across the Pacific Ocean from South America to the Polynesian islands, led by Norwegian explorer and writer Thor Heyerdahl. The raft was named Kon-Tiki after the Inca god Viracocha, for whom "Kon-Tiki" was said to be an old name. Heyerdal's book on the expedition was entitled The Kon-Tiki Expedition: By Raft Across the South Seas. A 1950 documentary film won the Academy Award for Best Documentary Feature. A 2012 dramatized feature film was nominated for the Academy Award for Best Foreign Language Film.

A raft is any flat structure for support or transportation over water. It is usually of basic design, characterized by the absence of a hull. Rafts are usually kept afloat by using any combination of buoyant materials such as wood, sealed barrels, or inflated air chambers, and are typically not propelled by an engine. Rafts are an ancient mode of transport; naturally-occurring rafts such as entwined vegetation and pieces of wood have been used to traverse water since the dawn of humanity.