Walter Bonatti (Italian pronunciation: [ˈvalter boˈnatti]; 22 June 1930 in Bergamo – 13 September 2011 in Rome) was an Italian mountain climber, explorer and journalist . He was noted for his many climbing achievements, including a solo climb of a new route on the south-west pillar of the Aiguille du Dru in August 1955, the first ascent of Gasherbrum IV in 1958 and in 1965 the first solo climb in winter of the North face of the Matterhorn on the mountain's centenary year of its first ascent. Immediately after his extraordinary solo climb on the Matterhorn Bonatti announced his retirement from professional climbing at the age of 35 and after 17 years of climbing activity. He authored many mountaineering books and spent the remainder of his career travelling off the beaten track as a reporter for the Italian magazine Epoca.
He died on 13 September 2011 of pancreatic cancer in Rome aged 81, and was survived by his life partner, the actress Rossana Podestà.
Famed for his climbing panache, he pioneered little known and technically difficult climbs in the Alps, Himalayas and Patagonia.