Sir Con Douglas Walter O'Neill was a British civil servant and diplomat. He was the British Ambassador to China (1955–1957) and the British Ambassador to Finland (1961–1963). He was also the British representative to the European Economic Community from 1963 to 1965 and led the British delegation which negotiated the country's entry to the EEC.
- Occupation
- diplomat, politician
- Position held
- United Kingdom Permanent Representative to the European Communities, ambassador of the United Kingdom to Finland
- Citizenship
- United Kingdom, United Kingdom of Great Britain and Ireland
- Born
- June 3, 1912
