The Deputy Secretary of State serves as the principal deputy to the U.S. Secretary of State and is crucial for continuity, stepping in as acting Secretary if the principal resigns or dies until a replacement is confirmed. This significant position was established in 1972, taking over the responsibilities previously held by the Under Secretary of State.

Uniquely among U.S. federal cabinet-level agencies, the State Department features two co-equal Deputy Secretaries, both fully authorized to act on behalf of the Secretary. The creation of this role marked a notable shift in the department's leadership structure. Historically, several distinguished individuals who held the Deputy Secretary position have gone on to become Secretary of State, including Lawrence Eagleburger (1992), Warren Christopher (1993), and most recently, Antony Blinken in 2021.