Ambassador Quainton (April 4, 1934 - July 31, 2023) was a Distinguished Diplomat in Residence at American University in Washington D.C.

He retired from the United State Foreign Service in 1997 after a 37-year career. During his career he served as Ambassador to Peru (1989-92), Kuwait (1984-87), Nicaragua (1982-84) and the Central African Republic (1976-78). In Washington he served as Coordinator for Counter Terrorism, Deputy Inspector General, Assistant Secretary of State for Diplomatic Security, and Director General of the Foreign Service. His other overseas posts included, Sydney, Australia, Karachi and Rawalpindi, Pakistan, New Delhi, India, Kathmandu, Nepal and Paris, France. After retiring from the Foreign Service he was Executive Director of the Una Chapman Cox Foundation (1997-98) and President and C.E.O. of the National Policy Association (1998-2003).

Ambassador Quainton was a member of the Council on Foreign Relations, the Washington Institute of International Affairs, and the American Academy of Diplomacy. He served as a Consultant to the International Policy Committee of the U.S. Conference of Catholic Bishops.

He was a graduate of Princeton University (1955) and Oxford University (1958), which he attended as a Marshall Scholar.

He is married to Susan Long Quainton, and has three children and seven grandchildren.