Kengo Hirachi (平地 健吾 Hirachi Kengo, born 30 November 1964) is a Japanese mathematician, specializing in CR geometry and mathematical analysis. Hirachi received from Osaka University his B.S. in 1987, his M.S. in 1989, and his Dr.Sci., advised by Gen Komatsu, in 1994 with dissertation The second variation of the Bergman kernel for ellipsoids. He was a research assistant from 1989 to 1996 and a lecturer from 1996 to 2000 at Osaka University. He was an associate professor from 2000 to 2010 and a full professor from 2010 to the present at the University of Tokyo. He was a visiting professor at the Mathematical Sciences Research Institute from October 1995 to September 1996, at the Erwin Schrödinger Institute for Mathematical Physics from March 2004 to April 2004, at Princeton University from O