Peter Jan Schoomaker (born February 12, 1946) is a retired four-star general of the United States Army and served as the 35th Chief of Staff of the United States Army from August 1, 2003 to April 10, 2007. Schoomaker's appointment as Chief of Staff was unique in that he was recalled and came out from retirement to assume the position. Schoomaker voluntarily retired from the Army for the second time in 2007 after completing the full four-year term as Chief of Staff. His brother, Lieutenant General Eric Schoomaker, M.D., PhD, was the 42nd Surgeon General of the United States Army.