Yoshiko Sato (佐藤 喜子, Satō Yoshiko, born March 30, 1938) is a retired Japanese freestyle swimmer who won seven gold medals at the Asian Games in 1958–1962.

She competed at the 1956 and 1960 Olympics in five sprint events in total with the best result of seventh place in the 4×100 m medley relay.

[1] In 1963, Sato retired from competitions and next year married Yoshihiko Osaki, a fellow swimmer who also competed at the 1960 Olympics.

Since 1985 she took part in all World and Pan Pacific championships, winning 20 world and 17 Pan Pacific titles and setting 93 world records in the freestyle, butterfly and medley events.

In 2005, she was inducted into the International Swimming Hall of Fame, in the masters category.