Stephen D. Mull (born April 30, 1958) is a Senior Foreign Service officer who was most recently the Acting Undersecretary of State for Political Affairs.

[4] In 2024, Secretary of State Antony Blinken appointed him to coordinate the peaceful transfer of power with the Trump Presidential Transition Team.

Missions in Poland, the Bahamas, and South Africa since the beginning of his career in the Foreign Service in 1982.

Prior to his assignment in Jakarta, Mull worked as Deputy Director of the State Department Operations Center, as Political Counselor at the U.S. Embassy in Warsaw, Poland, as Director of the Office of Southern European Affairs in the Bureau of European Affairs, and as Deputy Executive Secretary in the Office of the Secretary of State.

[7] On April 30, 2009, Mull testified before the U.S. Senate Foreign Relations Committee on international efforts to combat piracy off the coast of Somalia.