Merritt Roe Smith (1940) is an American historian. He is the Leverett and William Cutten Professor of the History of Technology at the Massachusetts Institute of Technology.
Smith graduated from Georgetown University, and Pennsylvania State University with a Ph.D. His research focuses on the history of technological innovation and social change. He is currently writing a monograph on technology and the American Civil War. Smith is a Fellow of the American Academy of Arts and Sciences, and he is past president of the Society for the History of Technology.