Joseph Leonard Ullman (30 January 1923, in Buffalo, New York – 11 September 1995, in Chelsea, Michigan) was a mathematician who worked on classical analysis with a focus on approximation theory.
from the University of Buffalo and his graduate studies were interrupted by service in the U.S. Army in World War II.
He was injured, received a Purple Heart, and spent the rest of the war as a mathematics instructor.
He received a Ph.D. in 1949 from Stanford University with thesis Studies on Faber Polynomials under the direction of Gábor Szegő.
During his career at the University of Michigan he supervised eleven doctoral theses.