The 1960 Valdivia earthquake or Great Chilean Earthquake (in Spanish, Gran terremoto de Valdivia ) of 22 May, 1960 is the most powerful earthquake ever recorded, rating 9.5 on the moment magnitude scale. It occurred in the early afternoon (19:11 UTC) and its resulting tsunami affected southern Chile, Hawaii, Japan, the Philippines, eastern New Zealand, south east Australia and the Aleutian Islands in Alaska.

The epicenter was near Cañete (see map) some 700 km south of Santiago although Valdivia, Chile was the most affected city. It caused localised tsunamis that severely battered the Chilean coast, with waves up to 25 metres. The main tsunami raced across the Pacific Ocean and devastated Hilo, Hawaii. Waves as high as 10.7 metres were recorded 10,000 kilometres from the epicentre, and as far away as Japan and the Philippines. The death toll and monetary losses arising from such a widespread disaster can never be precisely known. Various estimates of the total number of fatalities from the earthquake and tsunamis have been published, with the USGS citing studies with figures of 2231, 3000, or 5700 killed, and another source uses an estimate of 6000 dead. Different sources have estimated the monetary cost ranged from 400 million to 800 million US dollars (or 2.6 to 5.2 billion in 2005 dollars, adjusted for inflation.)