Okawa, died of natural causes this morning at a nursing home in Osaka, nursing home officials said.
Okawa was born to the family of a kimono shop owner in Osaka on March 5, 1898, the same year the US annexed the Hawaiian Islands and Pepsi-Cola was launched, 'Kyodo' news agency reported.
Okawa had credited her longevity to eating sushi and getting at least eight hours sleep a night.
Her 117th birthday celebrations last month were televised across Japan. Okawa had said that 117 years did not seem like such a long time.
Okawa took the title of world's oldest living person in June 2013 following the death of Jiroemon Kimura - also from Japan - who passed away at the age of 116.
The world's oldest person is now Gertrude Weaver of the US, who will turn 117 on July 4.
Okawa married in 1919; her husband, Yukio, ran his own business in Kobe and together they had three children - two daughters and a son.
After the passing of her husband in June 1931, she moved back to Osaka, surrounded by her children, 4 grandchildren and 6 great grandchildren.
The oldest person ever to have lived is also female, Jeanne Calment of France, who lived to 122 years and 164 days.
