Robert William Harper, Jr. (born 1957[2]) is a computer science professor at Carnegie Mellon University who works in programming language research.

Prior to his position at Carnegie Mellon, Harper was a research fellow at the University of Edinburgh.

[3] Harper made major contributions to the design of the Standard ML programming language and the LF logical framework.

Harper was named an ACM Fellow in 2005 for his contributions to type systems for programming languages.

In 2021, he received the ACM SIGPLAN Programming Languages Achievement Award for his "foundational contributions to our understanding of type theory and its use in the design, specification, implementation, and verification of modern programming languages".