The most recent ambassador is Linda Thomas-Greenfield, who was nominated by President Joe Biden and confirmed by the Senate on February 23, 2021.

[1][2] Henry Cabot Lodge Jr., a leading moderate Republican who lost his seat in the United States Senate to John F. Kennedy in the 1952 elections, was appointed ambassador to the United Nations in 1953 by Dwight D. Eisenhower in gratitude for the defeated senator's role in the new president's defeat of conservative leader Robert A. Taft for the 1952 Republican nomination and subsequent service as his campaign manager in the general election; Eisenhower raised the ambassadorship to Cabinet rank in order to give Lodge direct access to him without having to go through the State Department.

[3] The ambassadorship continued to hold this status throughout the remainder of the Cold War but was removed from Cabinet rank by George H. W. Bush, who had previously held the position himself.

[6] However, in December 2018, it was reported by several news organizations that the Trump administration would once again downgrade the position to non-Cabinet rank.

[8] Former UN ambassador and national security advisor John R. Bolton has publicly opposed the granting of Cabinet-level status to the office, stating "One, it overstates the role and importance the U.N. should have in U.S. foreign policy, second, you shouldn't have two secretaries in the same department".