was a Japanese academic, an historian and author. He was for many years a professor at the University of Tokyo.
Seiichi was born in Tokyo. He attended the University of Tokyo, graduating in 1925.
Seiichi was a member of the faculty of the University of Tokyo. His contribution to Japanese historiography is measured in the effect his teaching and example produced in a younger generation of students.
Iwao was considered a leading scholar in the colonial period of Indonesian history. His study of Japanese towns in South Asia before the Pacific War was published in . The research used documents of the Dutch East Indies Company in the archives of the Hague and Jakarta.
Iwao's research and writing covered a broad range, including his early work on Japanese emigrant communities in South Asia and his later work on the Edo period of national seclusion (sakoku).
In a statistical overview derived from writings by and about Seiichi Iwao, OCLC/WorldCat encompasses roughly 100+ works in 200+ publications in 7 languages and 1,500+ library holdings.