George Atkinson from Surbiton, near River Thames, climbed the 8,850 meter (29,035 feet) summit from the Tibetan side of the mountain which is adjacent to Nepal and China, British hiking group Adventure Peaks said on its website.
Atkinson was three day short of his 17th birthday when he broke the previous record holder American Johnny Collinson’s achievement of climbing seven summits when he was 17.
George Atkinson, the youngest teen who broke the world record to climb the Mount Everest, the agency said.
The British Mountaineering Council confirmed the record, the BBC reported on its website.
But there is no comment from Nepali government officials.
At the age of 11 in 2005, Atkinson's first conquered Kilimanjaro, Africa’s highest mountain
Atkinson was accompanied by 17 other climbers on Thursday, including Sherpa guides, said Himalayan Guides, the Nepali climbing group which provided local logistics.
More than 3,100 climbers have reached the top of Mount Everest since it was first climbed by New Zealander Sir Edmund Hillary and Sherpa Tenzing Norgay in 1953.
American Jordan Romero aged 13 is the youngest to have reached the peak, last year.