The Board of Regents is the governing body of the Smithsonian Institution, created by the Act of August 10, 1846, which established the Institution and gave form to the trust received from its English benefactor, James Smithson. The Board's composition has varied over time. At present it consists of two ex officio members, the Vice-President of the United States and the Chief Justice of the United States (by custom, its Chancellor), three members of the House of Representatives and three members of the Senate, appointed by resolution from those two bodies, and nine citizen-Regents, no two of whom may be residents of the same state, and two of whom must be residents of the District of Columbia. These members are appointed, upon recommendation of the Board, by joint resolution of the Congress.

The Secretary of the Smithsonian Institution is responsible for shaping the Institution's policies and directing its operations; but final authority resides with the Board of Regents, which is empowered to hold title to land, to accept gifts and trusts, to sue and be sued, and to exercise all the other powers usual to bodies of this kind.

Ad hoc committees are created to conduct certain orders of business, including Secretarial searches. The Executive Committee of the Board is a standing committee, and has existed since 1846. Likewise, the Audit and Review Committee, initially formed as an ad hoc committee in 1977, was re-established in 1979 as a standing committee to oversee the Institution's accounting systems and internal controls.

Chancellors of the Board of Regents have included: George Mifflin Dallas, 1846-1849; Millard Fillmore, 1849-1851; Roger B. Taney, 1851-1864; Salmon P. Chase, 1864-1873; Morrison R. Waite, 1874-1888; Melville Weston Fuller, 1888-1910; Edward Douglass White, 1910-1921; William H. Taft, 1921-1930; Charles Evans Hughes, 1930-1941; Harlan Fiske Stone, 1941-1946; Fred M. Vinson, 1946-1953; Earl Warren, 1953-1969; Warren E. Burger, 1969-1986; and William H. Rehnquist, 1986- .