Óscar Fanjul holds a PhD in economics, having been a visiting scholar at the Department of Economics at both Harvard University and the Massachusetts Institute of Technology (MIT). He is the founding chairman and former CEO of Repsol. He has also been chairman of Hidroeléctrica del Cantábrico, NHH and Deoleo. He is currently the vice chairman of Omega Capital and the vice chairman of LafargeHolcim. He is also a board member of The Marsh and McLennan Companies and of Ferrovial. He has also been vice chairman of Lafarge and a board member of Unilever, BBVA, the London Stock Exchange, Areva and Acerinox.

He is vice chairman of the Board of Trustees of the Museo Nacional Centro de Arte Reina Sofía and a trustee of the Instituto de Estudios Superiores de Empresa (IESE), of the Centro de Estudios Monetarios y Financieros (Bank of Spain) and of the Aspen Institute (Spain). He has also been a trustee of the International Financial Reporting Standards Committee