10 Year old conquers third African summit
Jack Harley-Walsh, from Ascot, climbed 17,057ft (5,199m) Mount Kenya with his mother Sue, reaching the summit at 1305 local time (1105 BST).
The young adventurer also climbed Tanzania's Mount Meru in July.
Money is being raised for the Thames Valley and Chiltern Air Ambulance Trust and charity Sebastian's Action Trust. Jack and his mother set off with a team of guides on Wednesday.
Kenyan-based tour operator Riz Virji, who organised the climb, said it was "rare" for a 10-year-old to have climbed three mountains in such a short space of time.
He said: "It was a very difficult climb due to the fact that there was winds and storms.
"The climb is much steeper than Kilimanjaro and you are climbing Kenya quicker.
"Usually they take on one mountain and that is it, so to do three in such a short space of time shows an incredible amount of energy."
Jack's grandmother Josie Walsh told the BBC she had received the news just minutes after the pair reached the top.
"I'm ready to burst into tears, it is so emotional," she said.
"We are just looking forward to seeing them when they return home, I'm sure there will be plenty of photographs. I'm very proud of them both."
Jack is now set to visit flamingoes at a national park to end his African adventure before returning home.
Put's some of us 'oldies' to shame