Fumio Hayashi (林 文夫, Hayashi Fumio?, born 18 April 1952) is a Japanese economist. As of October 2009, he is a professor at Hitotsubashi University in Tokyo. Hayashi was awarded the inaugural Nakahara Prize in 1995.
Hayashi took his Bachelor of Arts from the University of Tokyo and his Ph.D. from Harvard University in 1980. He has taught at Northwestern University, the University of Tokyo, the University of Tsukuba, Osaka University, the University of Pennsylvania, and Columbia University.
Hayashi is the author of a standard graduate-level textbook on econometrics.