Tamae Watanabe reached Everest’s 8,850-metre-high summit from the northern side of the mountain in Tibet with four other team members, Daily Mail reported.
A decade ago she became the oldest women to reach the top at the age of 63 but today smashed the record.
Weather conditions have been challenging this year, prompting several expeditions to cancel their plans to try to reach the summit.
May is considered the best month to climb Everest, when climbers get about two windows of good weather for their bid for the summit.
The oldest person to climb Everest is a Nepalese man, Min Bahadur Sherchan, who reached the peak in 2008 at the age of 76.