A specialization of public official (q.v.). Typically, a chief of staff heads the office or personal staff of an important public official. For example, the White House Chief of Staff is the highest-ranking member of the Executive Office of the President of the United States; a Congressional Chief of Staff heads the office of a member of the United States Congress.

Note that a chief of staff in the present sense is not to be confused with a military chief of staff. Cf. chief of staff, and see the specializations of US Army coordinating staff member.