Born in Koishikawa, Tokyo (present-day Bunkyo Ward) and raised in Kyoto. His father Ogawa Takuji was a geologist, and he grew up in an academic family with many scholars among his siblings. He studied physics at Kyoto Imperial University's Faculty of Science and in 1933 became an assistant professor at Osaka Imperial University (now Osaka University). In November 1934 he published his "meson theory," predicting the existence of mesons (mediating particles that bind neutrons and protons within atomic nuclei). Initially almost entirely ignored internationally, the theory was vindicated in 1947 when Britain's Powell and others actually discovered the pi meson (π meson) through cosmic ray observation. In 1949 he became the first Japanese person to receive the Nobel Prize in Physics. Receiving the prize just four years after defeat in war brought great hope and pride to the devastated Japanese people. In his later years he participated in the "Pugwash Conferences" nuclear disarmament movement, advocating for peace as a scientist. His autobiographical essays, "The Traveler," were beloved by many readers. The Research Institute for Fundamental Physics at Kyoto University (now the Yukawa Memorial Hall) continues to operate as an international center for physics research. He died at 74.

Introspective and valuing deep contemplation, a pure scholarly temperament. While absorbed in the world of research, in his later years he also developed deep interest in human themes of nuclear abolition and peace. Humble and quiet by nature, he consistently maintained deep convictions about science and peace.

As the first Japanese Nobel Prize winner, a symbol of Japan's postwar scientific recovery. Meson theory made a major contribution to the development of particle physics. He has become a spiritual touchstone for subsequent generations of Japanese scientists as "the person who opened the path to the Nobel Prize."