A bacteriologist of the Meiji and Taishō periods, born in Inawashiro, Fukushima Prefecture. In early childhood, he fell into an open hearth fire and suffered severe burns to his left hand; surgery restored its function and inspired him to pursue medicine. After emigrating to the United States, he achieved pioneering work at the University of Pennsylvania and the Rockefeller Institute for Medical Research, including the cultivation and isolation of syphilis spirochetes (1911). He devoted himself to research on yellow fever in South America and Africa, passionately seeking to identify the pathogen. In 1928, he contracted yellow fever during fieldwork in Accra, Ghana, and died at the age of 51. His portrait appeared on the ¥1,000 banknote (retired in 2004) and he is widely celebrated in Japanese education as a symbol of perseverance. His research linking syphilis and neurosyphilis became a cornerstone of modern medicine, though parts of his yellow fever findings later required revision.

A figure of indomitable perseverance who overcame poverty and physical disability. He was marked by pure scientific passion and a selfless dedication undeterred even by mortal danger. At the same time, he reportedly had a strong desire for fame and recognition, and sometimes prioritized speed over caution in his research.

His pioneering contributions to syphilis research earned him a permanent place in the history of world medicine. His life of overcoming adversity has been continuously used in Japanese education as a symbol of modernization and internationalization, and the Noguchi Hideyo Memorial Museum in Inawashiro, Fukushima, attracts many visitors.