His appointments began as a Commercial Counsellor at the Australian Embassy in Rome, and then becoming a Minister (Commercial) in the Department of Foreign Trade, Commercial Adviser to the Australian High Commission, London, and Deputy Head of the Australian mission to the European Economic Community. After leaving the mission at the EEC, he was appointed Ambassador and Permanent Representative from Australia to the OECD, serving from 1977 to 1980. After leaving Paris, Donovan was made Special Trade Delegate to the United Nations Office at Geneva from 1980 to 1982 whilst retaining his honorific title of Ambassador. After retiring from the Diplomatic Service, Donovan retired to Paris, France and became a member of the International Court of Arbitration. In 1994, he became a Vice-Chairman of the Court, and for this service was created a Chevalier in the Legion d’Honneur in 1998.