Robert Charles O'Brien Jr. (born June 18, 1966) is an American attorney who served as the twenty-seventh United States national security advisor from 2019 to 2021. He was the fourth and final person to hold the position during the presidency of Donald Trump.
- Occupation
- lawyer, diplomat, political staffer
- Position held
- United States National Security Advisor, Special Envoy for Hostage Affairs
- Citizenship
- United States
- Born
- June 18, 1966