Robert Edmund O'Malley Jr. (born 1939) is an American mathematician. O'Malley studied electrical engineering and mathematics at the University of New Hampshire, where he received his baccalaureate degree in 1960 and his master's in 1961. He then studied differential equations and singular perturbations at Stanford University, where he received his doctorate in mathematics in 1966. After brief appointments at the University of North Carolina (Chapel Hill), Bell Telephone Laboratories, the Courant Institute (New York University), and the Mathematics Research Center (the University of Wisconsin, Madison), O'Malley returned to New York University in 1968. He remained there, doing research on asymptotic methods and singular perturbations with Joseph Keller and a number of other stimulating coll