Lionel Tiger has served as a consultant to a variety of institutions and companies. He has been an expert witness in trials involving murder and injury as a result of initiations at colleges, among others. He has advised law firms and businesses concerned with sexual harassment issues and architectural and industrial design firms on the behavioral consequences of choices made by planners and designers.

He has been a consultant to the Director of Net Assessment in the Office of the Secretary of Defense on issues ranging from the role of cognition in affecting behavioral choices and the effect of such stimuli as drugs, fatigue, loneliness, sexuality, and morale on the conduct of individuals and organizations. He chaired a Study Session at the Naval War College in Newport RI for the Director of Net Assessment and the Secretary of the Air Force on the impact of new biosocial research on military issues. He has advised entities such as Upjohn (now Pharmacia), the Revlon Corporation, J. Walter Thompson, the Sawyer-Miller Group, the Office of the Secretary of the Navy, and the Science Advisory Board of the Secretary of the Air Force. He was a member of a task force established by the Secretary to analyze terrorism in the context of asymmetric warfare. He has consulted for Booz, Allen, and Hamilton as well as the Canadian Management Association and chaired a Board of Advisors for the magazine US NEWS and WORLD REPORT. He is currently a Senior Research Consultant to the National Institute of Public Policy in Fairfax VA on a project evaluating forms of military and political deterrence in the contemporary context.

In a more public realm, he has appeared on dozens of television and radio programs, including among others NPR, Charlie Rose, Nightline, the Today Show, the BBC, Canadian Broadcasting Corporation, CNN, and PBS as well as local shows in many cities in the USA, Canada, and Europe. He has been interviewed frequently and cited in a generous array of publications ranging from the New York Times to Rolling Stone, Vogue, the Wall Street Journal, the Toronto Globe and Mail, the Financial Times, New York Magazine, Men's Health, Business Week, Fortune, Cosmopolitan, Newsweek, the Observer of London, La Republica in Italy, and L'Express in France