Yasutaro Koide (小出 保太郎 Koide Yasutarō, March 13, 1903 – January 19, 2016) was a Japanese supercentenarian, who was the oldest living man in the world following the death of Sakari Momoi on July 5, 2015, until his own death on January 19, 2016.

Children: 7 children

Relatives:

• 9 grandchildren
• 1 great-grandchild

Koide was born on March 13, 1903, and worked as a tailor for a men's clothes shop in Tsuruga, Fukui. He moved to Nagoya when he was 107 years old, to live with his daughter. When he turned 110, Koide could still read newspapers without glasses and could eat without dentures. He became the oldest living person in Aichi Prefecture on March 31, 2014, following the death of Nagoya resident Tsuya Miura, who died at the age of 111.

On August 21, 2015, he was officially recognised as the oldest living man by Guinness World Records. When asked about the secret to his long life, Koide responded by stating that "the best thing is to not overdo" and recommending abstinence from smoking or drinking.

He died on January 19, 2016, of heart failure and pneumonia in a hospital in Nagoya.