Sachs is Director of the Center for Sustainable Development at Columbia University and President of the UN Sustainable Development Solutions Network.He is an SDG Advocate for United Nations (UN) Secretary-General António Guterres on the Sustainable Development Goals (SDGs), a set of 17 global goals adopted at a UN summit meeting in September 2015.

From 2001 to 2018, Sachs was Special Advisor to the UN Secretary General, and held the same position under the previous UN Secretary-General Ban Ki-moon and prior to 2016 a similar advisory position related to the earlier Millennium Development Goals (MDGs), eight internationally sanctioned objectives to reduce extreme poverty, hunger and disease by 2015. In connection with the MDGs, he had first been appointed special adviser to the UN Secretary-General in 2002 during the term of Kofi Annan.

Sachs is co-founder and chief strategist of Millennium Promise Alliance, a nonprofit organization dedicated to ending extreme poverty and hunger that has come under scrutiny from critics and was the subject of a book by the journalist Nina Munk.

From 2002 to 2006, he was director of the United Nations Millennium Project’s work on the MDGs. He is co-editor of the World Happiness Report with John F. Helliwell and Richard Layard. In 2010, he became a commissioner for the Broadband Commission for Sustainable Development, whose stated aim is to boost the importance of broadband internet in international policy.