Colin S. Gray (29 Desember 1943 – 27 Februari 2020) adalah penulis geopolitik berkebangsaan Britania-Amerika dan guru besar hubungan internasional dan direktur pusat kajian strategi di Universitas Reading.^[1] Ia juga anggota senior di National Institute for Public Policy.

Gray kuliah di Universitas Manchester dan Universitas Oxford. Ia bekerja di International Institute for Strategic Studies dan Hudson Institute, kemudian mendirikan National Institute for Public Policy di Washington, D.C. Ia pernah menjadi penasihat pertahanan untuk pemerintah Britania dan Amerika Serikat. Gray bekerja sebagai Penasihat Umum Komite Pengendalian dan Pelucutan Senjata kabinet Reagan pada tahun 1982 hingga 1987.^[2] Ia mengajar di Universitas Hull, Universitas Lancaster, Universitas York, Universitas Toronto, dan Universitas British Columbia.^[3] Gray telah menerbitkan 30 buku tentang sejarah militer dan kajian strategi.

Alex Marshall dari Universitas Glasgow mengkritik Gray karena ia terlalu menyanjung Harry S. Truman tanpa mempertimbangkan catatan sejarah. Gray juga dikritik karena tidak mengomentari kemampuan intelektual Truman yang biasa-biasa saja serta kebijakan-kebijakan Truman yang memulai Perang Dingin.^[4]

• Canadian Defence Policy: A Question of Priorities (Toronto: Clarke, Irwin, 1972).
• The Soviet-American Arms Race (Lexington, MA: Lexington Books, 1976).
• The MX ICBM and National Security (New York: Praeger, 1981).
• Strategic Studies: A Critical Assessment (Westport, CT: Greenwood Press, 1982).
• Strategic Studies and Public Policy:The American Experience (Lexington, KY: The University Press of Kentucky, 1982).
• American Military Space Policy: Information Systems, Weapon Systems, and Arms Control (Cambridge, MA:Abt, 1983).
• Nuclear Strategy and National Style (Lanham, MD: University Press of America, 1986)
• The Geopolitics of Super Power (Lexington, KY:University Press of Kentucky, 1988).
• War, Peace, and Victory:Strategy and Statecraft for the Next Century (New York: Simon and Schuster, 1990).
• House of Cards: Why Arms Control Must Fail (Ithaca, NY: Cornell University Press, 1992).
• The Leverage of Sea Power: The Strategic Advantage of Navies in War (New York: The Free Press, 1992).
• Weapons Don't Make War:Policy, Strategy, and Technology (Lawrence, KS:University Press of Kansas, 1993).
• The Navy in the Post-Cold War World:The Uses and Value of Strategic Sea Power (University Park, PA: Penn State University Press, 1994).
• Explorations in Strategy (Westport, CT: Greenwood Press, 1996; 1998 sec. ed. pb [Praeger]).
• The Second Nuclear Age (Boulder, CO: Lynne Rienner Publishers, 1999).
• Modern Strategy (Oxford: Oxford University Press, 1999).
• Strategy for Chaos: Revolutions in Military Affairs and Other Evidence of History (London: Frank Cass, 2002).
• The Sheriff: America's Defense of the New World Order (Lexington, KY: The University Press of Kentucky, 2004).
• Another Bloody Century: Future Warfare (London: Weidenfeld and Nicolson, 2005)
• Strategy and History:Essays on Theory and Practice (Abingdon, UK: Routledge, 2006).
• War, Peace, and International Relations. An Introduction to Strategic History (Abingdon, UK:Routledge, 2007).
• The Strategy Bridge: Theory for Practice (Oxford, UK; Oxford University Press, 2010)
• Airpower for Strategic Effect (Maxwell AFB, AL: Air University Press, 2012).
• Strategy and Defence Planning: Meeting the Challenge of Uncertainty (Oxford University Press, 2014).

• Gray, Colin S. (2011). "Harry S. Truman and the forming of American grand strategy in the Cold War, 1945–1953". Dalam Murray, Williamson; Sinnreich, Richard Hart; Lacey, James (ed.). The Shaping of Grand Strategy: Policy, Diplomacy and War. New York: Cambridge University Press. ISBN 978-0-521-76126-0. ;
• Marshall, Alex (2012). "The Shaping of Grand Strategy: Policy, Diplomacy and War. Edited by Williamson Murray, Richard Hart Sinnreich and James Lacey". History. 97 (326): 290–291.