An agricultural economist, educator, and international figure of the Meiji, Taishō, and early Shōwa periods. Born in Morioka, Iwate (Nanbu domain), he studied at Sapporo Agricultural College (present-day Hokkaido University) under the influence of Dr. William Smith Clark. He studied agricultural economics in the United States and Germany, then returned to Japan with his wife Mary Elkinton and devoted himself to research in agricultural economics and policy. In 1900 he published Bushido: The Soul of Japan in English, introducing the spiritual and ethical norms of the samurai to the Western world—it became a bestseller. As Under-Secretary-General of the League of Nations (1920–1926), he worked to elevate Japan's role in international society. He made major contributions to education as the first president of Tokyo Woman's Christian University and as principal of the First Higher School. Making mutual understanding across the Pacific his life's mission, he died in Victoria, Canada. His portrait appeared on the ¥5,000 banknote from 1984 to 2004.

An internationalist who made it his life's mission to serve as a bridge between East and West. As a Christian he carried a Western ethical outlook, while holding deep pride in and attachment to Japan's spiritual culture. Of a gentle, intellectual, diplomatic temperament, he consistently prioritized dialogue and mutual understanding.

Bushido remains a classic of Japanese cultural commentary written in English, still read around the world today. His work at the League of Nations demonstrated the role Japan should play in international society. Facilities and monuments preserving Nitobe's legacy remain at Hokkaido University, Morioka City in Iwate, Tokyo Woman's Christian University, and other sites.