Frank Graham Klotz (born September 7, 1950) served as Under Secretary of Energy for Nuclear Security and Administrator for the National Nuclear Security Administration of the U.S. Department of Energy.

He has also served on the faculty of the Air Force Academy, at NATO headquarters in Brussels, at the American Embassy in Moscow, Russia, and as the Director for Nuclear Policy and Arms Control with the National Security Council at the White House.

Between 2014 and 2018, Klotz served as Under Secretary of Energy for Nuclear Security, responsible for the management and operation of NNSA, as well as policy matters across the Department of Energy and NNSA enterprise in support of the president's nuclear security agenda.

In the 2024 United States presidential election, Klotz endorsed Kamala Harris.

This article incorporates public domain material from Major General Frank G. Klotz.