William Aaron Woods (b 1942) is a linguist and software engineer best known for his research in natural language processing, continuous speech understanding, knowledge representation, and knowledge-based search technology.

He earned his doctorate at Harvard University, where he then served as an Assistant Professor and later as a Gordon McKay Professor of the Practice of Computer Science. Woods built one of the first natural language question answering systems LUNAR while at Bolt Beranek and Newman (BBN) in Cambridge, Massachusetts. At BBN, he was a Principal Scientist and manager of the Artificial Inteligence Department in the 1970s and early 1980s. He was the principal investigator for BBN's early work in natural language processing and knowledge representation, as well as for its first project in continuous speech understanding. Subsequently, he was Chief Scientist for Applied Expert Systems, Inc. and Principal Technologist for On Technology Inc.. In 1991, he joined Sun Microsystems Laboratories as a Principal Scientist and Distinguished Engineer, and in 2007, he joined ITA Software, Inc. as a Distinguished Software Engineer.

He is a former president of the Association for Computational Linguistics, a Fellow of the American Association for Artificial Intelligence, and a Fellow of the American Association for the Advancement of Science.