Thordur is a native of Reykjavik, Iceland. He received the B.S. degree in electrical engineering and mathematics in 1983 from the University of Wisconsin, Madison, and the Ph.D. degree in electrical engineering systems in 1988 from the University of Michigan, Ann Arbor.

He was a research fellow and lecturer in the Department of Electrical Engineering and Computer Science at the University of Michigan in 1988. In 1989, he joined the Johns Hopkins University, Baltimore, MD, where he was Associate Professor of Electrical and Computer Engineering. Thordur has served on the faculty of the University of Iceland and as a principal engineering staff at United Technologies Research Center, East Hartford, CT. Currently he hold the position of Professor of Electrical and Computer Engineering at the University of Oklahoma.

Dr. Runolfsson's research interests include stochastic systems, control theory, complex dynamical systems, uncertainty analysis, modeling and simulation, power systems and energy efficiency, and intelligent transportation systems.