The Victoria College Prep pupil reached the summit with his dad, experienced mountaineer Fergus, on 27 December after four gruelling days in terrible weather conditions.
Battling against heavy rain which turned into driving snow above 3,000 metres, they made it to the top on the Machame route along which there is a near constant risk of rocks falling as the glacier above melts and releases rocks.
Oisin is not only the youngest person to summit via that route, but he has also become the fastest ten-year-old ever to climb the 5,864-metre peak.
