Louis F. O’Neill is an American diplomat and attorney. An expert on Russia/Eurasia conflicts and security, he served as Organization for Security and Co-operation in Europe Ambassador and Head of Mission to Moldova (2006–2008). O’Neill worked on the State Department's Policy Planning Staff (2005–2006), and as Special Assistant for Russian Affairs to Secretary of State Colin Powell (2004–2005) when O’Neill was a non-political, non-partisan White House Fellow.