Charles Max Mason (October 26, 1877 - March 23, 1961) was an American mathematician. Mason was president of the University of Chicago (1925-1929) and president of the Rockefeller Foundation (1929-1936). Mason's mathematical research interests included differential equations, the calculus of variations, and electromagnetic theory. He was a mathematics instructor at MIT, Yale and the University of Wisconsin-Madison. He was Chairman of the team directing the construction of the Palomar Observatory from 1936-1949. He died in 1961 at the age of 83.