General McPeak was born in Santa Rosa, California. After graduating from Grants Pass High School in Grants Pass, Oregon, he entered San Diego State College where he earned a B.A. in economics in 1957. He was commissioned through the Air Force ROTC program at the college, and entered active duty in November of that year. He also holds a master’s degree in international relations from George Washington University.
General McPeak is a fighter pilot veteran of the Vietnam War. After the war, he served as an air operations staff officer for the Mideast Division at Headquarters USAF in Washington. After graduating from the National War College in 1974, he was named assistant deputy commander for operations for the 1st Tactical Fighter Wing at MacDill AFB, Florida. He later (1975–76) was a military fellow with the Council on Foreign Relations in New York City.
In July 1976, he became commander of the 513th Combat Support Group based at RAF Station Mildenhall; a year later he moved to Zaragoza Air Base in Spain as vice commander of the 406th Tactical Fighter Training Wing. From 1978-80, he was assistant chief of staff for current operations, Allied Air Forces Central Europe (in Boerfink, West Germany). 1980-81 saw him commanding the 20th Tactical Fighter Wing, based at RAF Station Upper Heyford. General McPeak was chief of staff at USAFE headquarters from 1981–82, and deputy chief of staff for plans at TAC headquarters, Langley AFB, Virginia from 1982-85. He returned to Headquarters USAF in 1985-87 as deputy chief of staff for programs and resources.
In June 1987, General McPeak moved to Bergstrom AFB, Texas in the dual roles of 12th Air Force commander and commander of Air Forces for United States Southern Command. A year later he was named commander-in-chief of Pacific Air Forces PACAF. He was appointed Air Force Chief of Staff by President George H.W. Bush in October 1990, replacing the retiring General Michael Dugan.
General McPeak took over as Chief of Staff during the run-up for Operation Desert Shield, and assisted in overall strategic planning for Operation Desert Storm. His tenure also saw major reduction in force as a result of the end of the Cold War; during his time as Chief of Staff, he oversaw the disbandment of Strategic Air Command, Air Force Systems Command and Air Force Communications Command, with assets transferred primarily to Air Combat Command, Air Mobility Command, Air Force Materiel Command and the Air Force Communications Agency.
Following his Air Force career, General McPeak entered the private sector. He has been on the boards of directors for TWA, ECC International, where he served for several years as Chairman. General McPeak and his wife Elynor currently reside in Lake Oswego, Oregon. She serves as a member of the Lake Oswego City Council.