ジョン・ケイ（John Kay、1948年 - ）は、イギリスの経済学者。オックスフォード大学セント・ジョンズ・カレッジのフェローを務め、Institute for Fiscal Studies（IFS）の所長、London Business School教授、オックスフォード大学サイード・ビジネス・スクール初代ディレクターなどを歴任した。企業戦略、金融、市場経済、意思決定などを研究し、学術研究だけでなく企業経営や公共政策にも携わってきた。代表作『The Truth About Markets: Why Some Nations Are Rich but Most Remain Poor』（未邦訳）では、市場経済の強みを認めながら、自己利益の追求と規制緩和を重視する市場原理主義を批判。市場が有効に機能するためには、企業や制度だけでなく、社会的規範、信頼、文化といった背景が不可欠であることを、各国の経済や企業の事例を通して論じている。
John Kay (born 1948) is a British economist whose career has spanned academia, business, finance, and public policy. He is a Fellow of St John's College, Oxford, and has served as director of the Institute for Fiscal Studies, Professor of Economics at London Business School, and the first director of Oxford University's Saïd Business School. His work examines corporate strategy, finance, market economies, and decision-making, combining economic research with experience in business and public policy. In "The Truth About Markets: Why Some Nations Are Rich but Most Remain Poor," Kay defends the strengths of market economies while challenging market fundamentalism and the assumption that markets function primarily through individual self-interest. Drawing on economic and business examples from around the world, he argues that successful markets depend on institutions, social norms, trust, and culture.
