Merrill McPeak was born in 1936 in Santa Rosa, California. He was commissioned a 2d Lt in the U.S. Air Force through the ROTC program at San Diego State College on June 19, 1957, and went on active duty beginning November 30, 1957. After completing Officer Preflight Training, Lt McPeak attended pilot training and was awarded his pilot wings at Vance AFB, Oklahoma, in January 1959, followed by F-100 Super Sabre Combat Crew Training from February to December 1959. His first assignment was as an F-104 Starfighter pilot with the 436th Tactical Fighter Squadron (TFS) at George AFB, California, from December 1959 to August 1961, and then as an F-100 pilot with the 79th TFS at RAF Woodbridge, England, from August 1961 to May 1964. Capt McPeak then served on the staff of Headquarters 3rd Air Force at South Ruislip AS, England, from May 1964 to August 1965, followed by service as an F-104 instructor pilot with the 4443rd Combat Crew Training Squadron and as an F-104 weapons officer with the 4510th Combat Crew Training Wing at Luke AFB, Arizona, from September 1965 to December 1966. His next assignment was as an F-100 pilot with the U.S. Air Force Thunderbirds Air Demonstration Squadron at Nellis AFB, Nevada, from December 1966 to December 1968. Maj McPeak then deployed to Southeast Asia where he served as an F-100 pilot with the 612th TFS at Phu Cat AB, South Vietnam, from December 1968 to January 1969, followed by service as Operations Officer of the Misty Fast FACs at Phu Cat from February to April 1969. He then served as Commander of the Misty Fast FACs at Phu Cat and then at Tuy Hoa AB, South Vietnam, from April to August 1969, and was Chief of Stan/Eval for the 31st Tactical Fighter Wing (TFW) at Tuy Hoa AB from August to December 1969. He attended Armed Forces Staff College at Norfolk, Virginia, from January to July 1970, and then served as a staff officer with Headquarters U.S. Air Force in the Pentagon from August 1970 to August 1973. Col McPeak next attended National War College at Fort Lesley J. McNair in Washington, D.C., from August 1973 to June 1974, followed by service as Assistant Deputy Commander for Operations of the 1st TFW at MacDill AFB, Florida, from June 1974 to April 1975. He attended French Language Training at the Foreign Service Institute in Washington, D.C., from April to June 1975, and then received an assignment as a Military Fellow with the Council on Foreign Relations in New York City from July 1975 to June 1976. His next assignment was as Commander of the 513th Combat Support Group at RAF Mildenhall, England, from July 1976 to July 1977, followed by service as Vice Commander of the 406th Tactical Fighter Training Wing at Zaragoza AB, Spain, from July 1977 to July 1978. Col McPeak served as Assistant Chief of Staff for Current Operations with Allied Air Forces Central Europe at Boerfink, West Germany, from July 1978 to February 1980, and then as Commander of the 20th TFW at RAF Upper Heyford, England, from February 1980 to June 1981. Gen McPeak then served as Chief of Staff with Headquarters U.S. Air Forces in Europe at Ramstein AB, West Germany, from June 1981 to October 1982, followed by service as Deputy Chief of Staff for Plans with Headquarters Tactical Air Command at Langley AFB, Virginia, from October 1982 to May 1985. His next assignment was as Deputy Chief of Staff for Programs and Resources with Headquarters U.S. Air Force at the Pentagon from May 1985 to June 1987, and then as Commander of 12th Air Force and U.S. Southern Command Air Forces at Bergstrom AFB, Texas, from June 1987 to July 1988. Gen McPeak served as Commander-in-Chief of Pacific Air Forces at Hickam AFB, Hawaii, from July 1988 to October 1990, followed by service as the 14th Chief of Staff of the U.S. Air Force from October 30, 1990, to October 25, 1994, retiring from the Air Force on November 1, 1994. Merrill McPeak was Misty 94.

His Silver Star Citation reads:

Major Merrill A. McPeak distinguished himself by gallantry in connection with military operations against an opposing armed force over Southeast Asia on 11 April 1969. On that date, as an F-100F pilot and Forward Air Controller, Major McPeak directed a strike flight of fighters against two active hostile gun sites. With intense antiaircraft fire directed at his aircraft, he courageously pressed the target to minimum delivery parameters to insure an accurate mark for the strike fighters. His unwavering calmness and courage in the face of grave personal danger, together with his exceptional airmanship and skill in directing strike aircraft, resulted in the destruction of two antiaircraft gun positions. By his gallantry and devotion to duty, Major McPeak has reflected great credit upon himself and the United States Air Force.