The son of Frederick Corbett, of Chaddesley Corbett, Worcestershire, Corbett was educated at Bromsgrove School and was already a climber while still there. In 1898, when he was seventeen, he made his first climbing trip to Switzerland, visiting the central Alps and climbing the Grand Muveran, the Dent de Morcles, and peaks around Zermatt. In 1899 arrived as a classical scholar at Hertford College, Oxford, and in 1901 he made a second trip to the Alps, when he made a traverse of the Aiguilles Rouges, among other routes. While at Oxford he also climbed in Yorkshire and the Lake District, usually with his friend Alfred Barran. However, after taking a double first in Classics he entered the Indian Civil Service in 1904 and was lost to serious climbing for some years.