Koto Okubo (大久保 琴 Ōkubo Koto, 24 December 1897 – 12 January 2013) was a Japanese supercentenarian who, at the time of her death aged 115 years and 19 days, was recognized as the oldest woman in the world and the second oldest living person behind Jiroemon Kimura. At the time of her death, Okubo was one of only 29 people verified to have surpassed a 115th birthday.

Koto Okubo became the oldest woman from Japan and Asia after the death of Chiyono Hasegawa on 2 December 2011. The Ministry of Health, Labour and Welfare did not announce her name officially (only her residence and age were released). Furthermore, at that time, her record was not identified and recognized by the Gerontology Research Group.

The name of Okubo was finally reported by the Japanese press on 14 September 2012, and on the same day, Okubo was verified and added to the GRG list and Guinness World Records.

Okubo lived in a nursing home in Kawasaki, Kanagawa with her son. She died of pneumonia on 12 January 2013.