Tomiko Itooka, who was born on May 23, 1908, lives in the western Japanese city of Ashiya, the US-based Gerontology Research Group said.
She is next in line for the title of world's oldest person after Maria Branyas Morera died in a Spanish nursing home on Monday, according to the group.
Itooka, a mother-of-three, was born in the year when a long-distance radio message was sent from the Eiffel Tower for the first time, and when the Wright Brothers made their first public flights in Europe and America.
In her 70s, Itooka often went climbing and twice scaled Japan's 3,067-metre (10,062-ft) Mount Ontake - surprising her guide by climbing the mountain in sneakers instead of hiking boots, the research group said.
At the age of 100, she walked up the lengthy stone steps of Japan's Ashiya Shrine without using a cane, the group added.
