Maurice Frederick Strong, (April 29, 1929 – November 27, 2015) was a Canadian oil and mineral businessman and a diplomat who served as Under-Secretary-General of the United Nations.

Strong had his start as an entrepreneur in the Alberta oil patch and was President of Power Corporation of Canada until 1966. In the early 1970s he was Secretary General of the United Nations Conference on the Human Environment and then became the first executive director of the United Nations Environment Programme. He returned to Canada to become Chief Executive Officer of Petro-Canada from 1976 to 1978. He headed Ontario Hydro, one of North America's largest power utilities, was national president and chairman of the Extension Committee of the World Alliance of YMCAs, and headed American Water Development Incorporated. He served as a commissioner of the World Commission on Environment and Development in 1986 and was recognised by the International Union for Conservation of Nature as a leader in the international environmental movement.

He was President of the Council of the University for Peace from 1998 to 2006. More recently Strong was an active honorary professor at Peking University and honorary chairman of its Environmental Foundation. He was chairman of the advisory board for the Institute for Research on Security and Sustainability for Northeast Asia. He died at the age of 86 in 2015.