John Samuel Hagelin (born June 9, 1954) is an American particle physicist, three-time candidate of the Natural Law Party for President of the United States (1992, 1996, and 2000), and the director of the Transcendental Meditation movement for the US.

Hagelin was a researcher at the European Organization for Nuclear Research (CERN) and the Stanford Linear Accelerator Center (SLAC), and is now Professor of Physics and Director of the Institute of Science, Technology and Public Policy at Maharishi University of Management. He has conducted research into unified field theory and the Maharishi Effect.

Hagelin was appointed Raja of Invincible America by Maharishi Mahesh Yogi and is also President of the US Peace Government. He is Executive Director of the International Center for Invincible Defense, Executive Director of the Global Financial Capital of New York,^[3] Executive Director of the Center for Leadership Performance,^[4] Director of the Board of Advisors for the David Lynch Foundation,^[5] Honorary Chairman of the Board of Trustees of Maharishi University of Management,^[6] and International Director of the Global Union of Scientists for Peace.^[7]