Gabriel Keller (born 12 August 1947 in Paris, France) is a French diplomat and teacher. Keller earned a history professor agrégé degree in 1972 at Paris West University Nanterre La Défense.
He graduated from the École nationale d'administration (ENA) in 1979 and began his diplomatic career by joining the Ministry of Foreign and European Affairs (France) (MFA). His position took him to several French embassies abroad, which led him to hold various responsibilities within the United Nations and the Organization for Security and Co-operation in Europe (OSCE).
He completed his military obligations at the French lycee of Puducherry in India.
Keller held various teaching posts in India and Tunisia between 1967 and 1976.
Within the MFA, Gabriel Keller served as Coordinator at the Cultural, Scientific and Technical relations from 1979 until 1982; as First Counselor at the French embassy in Kuala Lumpur, Malaysia from 1982 until 1984; and as Counselor at the French Permanent Mission to the International Organisations in Vienna, Austria from 1984 until 1986.
While at the Ministry of Foreign and European Affairs in Paris, Keller was head of the Methods, Training and Computing Department from 1986 until 1989. He was then appointed deputy Director of the Department of UN and International Organisations, as member of the National Consultative Committee for Human Rights and member of the French delegation to the United Nations General Assembly between 1989 and 1993.