Jeffrey David Sachs (born November 5, 1954) is an American economist, public policy analyst, and director of the Earth Institute at Columbia University, where he is a professor. He is known as one of the world's leading experts on economic development and the fight against poverty.

Jeffrey Sachs is Professor of Sustainable Development at the School of International and Public Affairs and Professor of Health Policy and Management at Columbia University School of Public Health. Since 2017 he has been serving as Special Adviser to the Secretary-General of the United Nations António Guterres on the Sustainable Development Goals (SDGs). He held the same position under General Secretary Ban Ki-Moon, while before 2016, he served in a similar advisory position on the Millennium Sustainable Goals.

In 1995, Prof. Sachs became a member of the International Advisory Board of the Center for Social and Economic Research (CASE). He is co-founder and head of strategy of the Millennium Promise Alliance, a non-profit organization dedicated to ending extreme poverty and hunger. From 2002 to 2006, he was the director of the United Nations Millennium Development Goals Millennium Development Goals project. He is Director of the United Nations Network for Sustainable Development (SDSN) and co-author of the Global Happiness Report with John F. Helliwell and Richard Layard. In 2010, he became a member of the Broadband Committee for Sustainable Development, which aims to enhance the importance of broadband in international politics. Prof. Sachs has authored many books and has received numerous awards for excellence.