Noel Ewart Odell (25 December 1890 – 21 February 1987) was an English geologist and mountaineer. Born on the Isle of Wight, educated at Brighton College and the Royal School of Mines, Imperial College, in 1924 he was an oxygen officer on the Everest expedition in which George Mallory and Andrew Irvine famously perished during their summit attempt. Odell spent two weeks living above 23,000 feet (7,000m), and twice climbed to 26,800-ft and higher, all without supplemental oxygen.
On 8 June 1924 George Mallory and Andrew Irvine attempted to climb to the top of Mount Everest via the Northeast Ridge route. Keen-sighted Odell reported seeing them at 12:50 p.m. ascending one of the major "steps" on the North-East ridge, "the last step but one from the base of the final pyramid" and "going strongly for the top." But no evidence thus far has proved that they reached the summit, or that they ascended above the major Second Step. They never returned and perished on the mountain. Odell was the last person to see the pair alive.
In his first two accounts, written between June and November 1924, Odell was certain he had seen Mallory and Irvine climbing the Second Step. But in the expedition account published in 1925, and after mounting skepticism from members of the climbing community as to whether it was the Second Step or the lower First Step, Odell conceded it might have been the First Step where he had seen the pair. After he had been rejected as too old for the next Everest expedition, he recanted his change of mind and returned to the belief that he had seen the two climbers surmount the Second Step. Had they done so, there would have been a fair chance that one of them, at least, might have reached the summit.
In 1936 Noel Odell with Bill Tilman successfully reached the summit of Nanda Devi which at the time, and until 1950, was the highest mountain climbed. Odell returned to Everest with the expedition led by Tilman in 1938.