John D. Marks (born 1943) is the founder and former president of Search for Common Ground (SFCG), a non-profit organization based in Washington, DC that focuses on international conflict management programming. Marks now acts as a Senior Adviser to SFCG. He is also a former Foreign Service Officer of the U.S. Department of State and co-authored the 1974 controversial non-fiction book The CIA and the Cult of Intelligence with Victor Marchetti.