Thomas Joscelyn

Thomas Joscelyn (born 1976) is an American counterterrorism expert. He is a senior fellow at JustSecurity.org, an initiative of the Reiss Center on Law and Security at New York University School of Law. As a former senior fellow at the Foundation for Defense of Democracies, Joscelyn founded and was a senior editor for FDD's Long War Journal, a publication dealing with counterterrorism and related issues. He has served as a trainer for the FBI Counterterrorism Division, as well as being a principal author of the final report for the United States House Select Committee on the January 6 Attack.

Joscelyn's work has been published in publications including The New York Times, Politico, The Daily Beast, and The Weekly Standard. He has also been cited by The Washington Post, The Associated Press, Reuters, USA Today, and Time. In 2023, he was featured in an interview on 60 Minutes.