James Alexander Hendler (born April 2, 1957, in Queens, New York, United States) is an artificial intelligence and Semantic Web researcher affiliated with Rensselaer Polytechnic Institute and the University of Maryland, and is considered one of the originators of the Semantic Web.^[1,6] He is a Fellow of the National Academy of Public Administration and is recognized for Significant Contributions to the Semantic Web.^[1]

He attended Yale University, Southern Methodist University, and Brown University, completing his 1986 dissertation "Integrating Marker-Passing and Problem-Solving: A Spreading-Activation Approach to Improved Choice in Planning" under advisor Eugene Charniak. His notable students include Jen Golbeck.

Hendler completed his Doctor of Philosophy degree at Brown University in 1986 with a thesis on automated planning and scheduling.^[3] He also holds an MSc (1983) from Brown University, an MS (1981) in Cognitive Psychology from Southern Methodist University, and a BS (1978) from Yale University.

James A. Hendler's research interests are in the semantic web and artificial intelligence.^[7,8,4] In 2001, he co-authored the article "The Semantic Web" in Scientific American along with Tim Berners-Lee and Ora Lassila. Hendler held a longstanding position as a professor at the University of Maryland, where he served as the Director of the Joint Institute for Knowledge Discovery and held joint appointments in the Department of Computer Science, the Institute for Advanced Computer Studies, and the Institute for Systems Research. He was also the Director for Semantic Web and Agent Technology at the Maryland Information and Network Dynamics Laboratory.

On June 14, 2006, Hendler was appointed senior constellation professor of the Tetherless World Constellation at Rensselaer Polytechnic Institute (RPI), officially becoming a professor at the institute on January 1, 2007. Hendler helps lead the Tetherless World Constellation on increasing access to information at any time and place without the need for a "tether" to a specific computer or device, working toward a vision in which personal digital assistants (PDAs), cameras, music-listening devices, cell phones, smartphones, laptops, and other technologies converge to offer interactive information and communication.^[14] Hendler holds appointments in Computer, Web and Cognitive Sciences at RPI, and served as the Dean for Information Technology and Web Science from 2009 to 2012. In 2012, he became the Head of the Computer Science Department at RPI, and in 2013, he became the Director of the RPI Institute for Data Exploration and Applications.^[9] In 2017, he became the Rensselaer lead of the joint RPI-IBM Center for Health Empowerment by Analytics, Learning and Semantics (HEALS), a member of the IBM Artificial Intelligence Horizons Network.^[11,10] In 2019, Hendler was named Director of the RPI-IBM Artificial Intelligence Research Collaboration, a major joint project between IBM Research and RPI.^[12] He became the Founding Director of Rensselaer's Future of Computing Institute in 2022, and in 2025 he became the head of RPI's cognitive science department.^[13]

Hendler is a former member of the US Air Force Science Advisory Board and a former Chief Scientist of the Information Systems Office at DARPA. During his DARPA tenure, he was responsible for projects such as the Control of Agent Based Systems (CoABS) program, which led to other agent-based projects including the Taskable Agent Software Kit (TASK) and DARPA's Agent Markup Language (DAML), which contributed funding to the emerging Semantic Web area.^[15] He also served as an "Internet Web Expert" for the U.S. government, providing guidance to the Data.gov project, and was appointed Open Data Advisor for New York State in September 2013.^[1,16] In 2015, Hendler was appointed a member of the US Homeland Security Science and Technology Advisory Committee (HSSTAC), in 2016 to the National Academies Board on Research Data and Information, and in 2017 to the Director's Advisory Committee for the National Security Directorate at PNNL. In 2018, he was appointed chair of the Association for Computing Machinery's US Technology Policy Committee (USTPC, formerly USACM), and in 2021 he became chair of the ACM's Global Technology Policy Council.^[17] Hendler is the former chair of the board of directors of the Web Science Trust and has been a visiting professor at Hebrew University, DeMontfort University, Bath Spa University, and the University of Edinburgh, as well as an honorary professor at Wuhan University and the University of Leicester. He is the Editor in Chief Emeritus of IEEE Intelligent Systems and was the first computer scientist to serve on the Board of Reviewing Editors for Science. Hendler is a Fellow of the American Association for Artificial Intelligence, the British Computer Society, the Institute of Electrical and Electronics Engineers, the AAAS, the Association for Computing Machinery, and the National Academy of Public Administration, to which he was elected in 2018.^[2,17,19] Since 2018, he has been a regular participant on the Roundtable Panel at WAMC radio, and in 2021 he became a member of the Board of Trustees of WAMC.

His earlier publications include Integrating Marker-Passing and Problem Solving (Lawrence Erlbaum, 1987, ISBN 0-89859-982-2) as well as the edited volumes Expert Systems: The User Interface (Ablex Pub, 1988, ISBN 0-89391-429-0), Massively Parallel Artificial Intelligence (AAAI Press, 1994, ISBN 0-262-61102-3), and Robots for Kids (Morgan Kaufmann, 2000, ISBN 1-55860-597-5). In the field of the Semantic Web and internet research, he edited Spinning the Semantic Web (MIT Press, 2005, ISBN 0-262-56212-X) and co-authored Semantic Web for the Working Ontologist with Dean Allemang and Fabien Gandon (Morgan Kaufmann, 2008, ISBN 1450376142; second edition 2011; third edition 2020). His subsequent works include Web Science: Understanding the Emergence of Macro-Level Features on the World Wide Web, co-authored with Kieron O'Hara, Noshir Contractor, Wendy Hall, and Nigel Shadbolt (NOW publishers, 2013), and Social Machines: The coming collision of artificial intelligence, social networking and humanity, co-authored with Alice Mulvehill (Apress, 2016, ISBN 978-1-4842-1157-1). He also co-edited Linking the World’s Information: Essays on Tim Berners-Lee’s Invention of the World Wide Web with O. Seneviratne (ACM Press, 2023).

In 1995, they received a Fulbright Foundation Fellowship, followed by election as a Fellow of the AAAI in 1999. They were awarded the Department of the Air Force Decoration for Exceptional Civilian Service in 2002 and the Robert Engelmore Memorial Lecture Prize from the AAAI in 2005. In 2007, they were elected a Fellow of the British Computer Society, and in 2009 became a Fellow of both the IEEE and the Semantic Technology Institute International.

In 2010, they were named to Playboy magazine's "Honor Roll" of the 20 most innovative US professors, and were also named an "Internet Web Expert" for the US Office of Science and Technology Policy. They became a Fellow of the American Association for the Advancement of Science in 2012, were named Open Data Advisor for the New York State Government in 2013, and received an IBM Faculty Research Award in 2014. In 2015, they were appointed as a Member of the US Homeland Security Science and Technology Advisory Committee. In 2016, they were appointed a Member of the National Academies' Board on Research Data and Information and became a Fellow of the Association for Computing Machinery.

They received the AAAI Distinguished Service Award in 2017 and were named a Fellow of the National Academy of Public Administration (United States) in 2018. In 2021, they served as chair of the Global Technology Policy Council for the Association for Computing Machinery. They were appointed an Honorary Professor and Fellow at the University of Leicester in 2022, earned the Service Award from the Semantic Web Science Association in 2023, and joined the Steering Committee of the AI Alliance in 2024. They were a recipient of the 2025 AAAI, and in 2026 received, along with Tim Berners-Lee and Ora Lassila, the Lifetime Achievement award at the Knowledge Graph Conference.

The individual has served on the Board of Trustees for both WAMC Public Radio and Trinity Alliance (NGO). Additionally, they are a board member and former chair of the Board for the Web Science Trust. They have also served on the Advisory Boards of Timbr.AI, Radar Networks (sold to EVRI), TopQuadrant, Franz Inc, Bright Hub, SocialWire, and Common Crawl.