Ralph E. Johnson is a Research Associate Professor in the Department of Computer Science at the University of Illinois at Urbana-Champaign. He is a co-author of the influential computer science textbook Design Patterns: Elements of Reusable Object-Oriented Software, for which he won the 2010 ACM SIGSOFT Outstanding Research Award. In 2006 he was awarded the Dahl–Nygaard Prize for his contributions to the state of the art embodied in that book as well.