Kiyo Satō was born in the village of Kiyokawa (now part of Bungo-Ōno), Ōita Prefecture, Japan, on 13 September 1910. She played volleyball during her youth. At the age of 26, she married Ichio, a man from the nearby town of Ogatamachi Masebata. Together, they raised a family and had children.

Satō lived at home until the age of 104, at which point she entered a nursing home for the elderly. In 2018, the governor of Ōita Prefecture visited her as part of a celebration for her 108th birthday. The event was attended by her grandchildren, fellow nursing home residents, and staff. The governor presented her with a cotton blanket, and she received a round of applause from everyone present. In response, she expressed her surprise and gratitude by saying, “I’m surprised. Thank you.” Even at the age of 108, she reportedly maintained a hearty appetite and could use chopsticks to eat her meals without assistance. At that time, she was the 11th-oldest living person in Ōita Prefecture. In 2019, she was admitted to the hospital due to a deterioration in her condition, but she quickly recovered and returned to her nursing home. Satō was not picky when it came to food. When asked about the secret to longevity, she responded, “Not worrying about things.”

Kiyo Satō passed away in Bungo-Ōno, Ōita Prefecture, Japan, on 30 April 2021, at the age of 110 years, 229 days.