Edwin Oldfather Reischauer (October 15, 1910 - September 1, 1990) was Tokyo-born U.S ambassador to Japan (1961-66) and the co-developer, with George M. McCune, of the McCune-Reischauer romanization of Korean.

He graduated with a B.A from Oberlin in 1931 and received his Ph.D from Harvard University in 1939. Most of his teaching career was spent at Harvard, where he was the director of the Harvard-Yenching Institute and chairman of the Department of Far Eastern Languages. At Harvard, he was the founder of the Japan Institute, which was renamed the Edwin O. Reischauer Institute of Japanese Studies in 1985 in his honor.