Marion Hartzog Smoak (July 8, 1916 – May 4, 2020) was an American attorney and politician who served as Chief of Protocol of the United States under President Richard Nixon from 1972 to 1974.

Commissioned into the United States Army, Smoak served in the Judge Advocate General's Corps in both the Pacific and European Theaters during World War II, then taught military law at the United States Military Academy.

Occupation Forces in Japan, where his duties included overseeing war crimes trials of Japanese military members; this was followed by tours with the 82d Airborne Division at Fort Bragg, North Carolina, and the 101st Airborne Division at Fort Campbell, Kentucky, during which he qualified for the Master Parachutist Badge by making 58 jumps.

[6] During his tenure, he oversaw several major events, including the state funerals of Presidents Dwight D. Eisenhower, Harry S. Truman and Lyndon B. Johnson, and state visits by Soviet Premier Leonid Brezhnev and Prince Charles.

He subsequently returned to private law practice at the Washington, D.C. firm of Shipley, Smoak and Henry.