Muller (born January 6, 1944) is an American physicist and professor of physics at the University of California, Berkeley.
He is also a faculty senior scientist at the Lawrence Berkeley National Laboratory.
Most recently, in early 2010, Muller and his daughter Elizabeth founded the group Berkeley Earth, an independent 501(c)(3) non-profit aimed at addressing some of the major concerns of the climate change skeptics, in particular the global surface temperature record.