Peter Pace is a retired United States Marine Corps general who served as the 16th chairman of the Joint Chiefs of Staff. Pace was the first Marine officer appointed as chairman and the first Marine officer to be appointed to three different four-star assignments; the others were as the sixth vice chairman of the Joint Chiefs of Staff from October 1, 2001, to August 12, 2005, and as Commander-in-Chief, U.S. Southern Command from September 8, 2000, to September 30, 2001. Appointed chairman by President George W. Bush, Pace succeeded U.S. Air Force General Richard Myers on September 30, 2005.

The chairman of the Joint Chiefs of Staff (CJCS) is the presiding officer of the Joint Chiefs of Staff (JCS). The chairman is the highest-ranking and most senior military officer in the United States Armed Forces and the principal military advisor to the president, the National Security Council, the Homeland Security Council, and the secretary of defense. While the chairman of the Joint Chiefs of Staff outranks all other commissioned officers, the chairman is prohibited by law from having operational command authority over the armed forces; however, the chairman assists the president and the secretary of defense in exercising their command functions.