Horng-Tzer Yau (Chinese: 姚鴻澤; pinyin: Yáo Hóngzé; born 1959 in Taiwan) is a Taiwanese-American mathematician. He received his B.Sc. in 1981 from National Taiwan University and his Ph.D. in 1987 from Princeton University. Yau joined the faculty of NYU in 1988, and became a full professor at its Courant Institute of Mathematical Sciences in 1994. He moved to Stanford in 2003, and then to Harvard University in 2005. He was also a member of the Institute for Advanced Study in Princeton, New Jersey, in 1987-88, 1991–92, and 2003, and was a Distinguished Visiting Professor in 2013-14.
According to William C. Kirby, dean of the Faculty of Arts and Sciences at Harvard, "Professor Yau is a leader in the fields of mathematical physics, ... who has introduced important tools and concepts to study probability, stochastic processes, nonequilibrium statistical physics, and quantum dynamics."
- Simons Investigator Award 
- Sloan Foundation Fellowship
- Packard Foundation Fellowship, 1991
- Henri Poincaré Prize, 2000
- MacArthur Fellowship, 2000
- Morningside Gold Medal of Mathematics, 2001 
- Academician of the Academia Sinica
- Member of the American Academy of Arts and Sciences
- Member of the National Academy of Sciences 
- Fellow of the American Mathematical Society, 2012
- Simons Investigator, 2012
- Editor-in-Chief of Communications in Mathematical Physics
- the 2017 Eisenbud Prize for Mathematics & Physics
- Harvard University Gazette April 14, 2005
- 2012 Simons Investigators September, 2012
- H.-T. Yau Receives MacArthur Fellowship October, 2000
- Notices of the AMS May, 2002
- News from the National Academy of Sciences Archived 2016-04-04 at the Wayback Machine. April, 2013
- List of Fellows of the American Mathematical Society, retrieved 2013-09-01.
- Simons Investigators Awardees, The Simons Foundation