David O'Sullivan (born 1 March 1953) is serving as the EU Sanctions Envoy since January 2023.

[3][4] O'Sullivan has held a number of high level positions including Chief of Staff to President Romano Prodi and Secretary-General of the European Commission between June 2000 and November 2005.

General Gerald (Gerry) O’Sullivan was formerly Chief of staff of the Irish Defence Forces.

In 2005, he was appointed Director General for Trade where he acted as Chief Negotiator for the Doha Development Round.

[6] O'Sullivan was appointed to the post of Ambassador of the European Union to the United States, taking up office in Washington, D.C., on 1 November 2014.

[9] He presented his credentials to President Barack Obama at a White House ceremony on 18 November 2014.