Greg Lewis was born on March 21, 1953, and is a resident of York, Pennsylvania. He enlisted in the U.S. Air Force Reserve on July 13, 1971, and entered the U.S. Air Force Academy in June 1972. He was commissioned a 2d Lt in the U.S. Air Force on June 2, 1976, and while at the Academy he was a member of the Wings of Blue parachute team. Lt Lewis next attended Undergraduate Pilot Training at Laughlin AFB, Texas, where he was awarded his pilot wings on June 29, 1977. He was then assigned in the first group of Lieutenants to fly the new A-10 Thunderbolt II at Myrtle Beach AFB, South Carolina, completing his training in February 1978. Lt Lewis served as an A-10 pilot at Myrtle Beach AFB from February 1978 to June 1979, and then as an A-10 pilot, instructor pilot, and Squadron Weapons Officer at RAF Bentwaters/Woodbridge, England, from June 1979 to October 1982. During this time he attended the A-10 Fighter Weapons School at Nellis AFB, Nevada. Capt Lewis was selected for an Air Staff Training Assignment at the Pentagon in 1982, serving there from October 1982 to March 1984. His next assignment was as an F-16 Fighting Falcon pilot and Wing Weapons Officer at Kunsan AB, South Korea, from March 1984 to May 1985, followed by service as aide-de-camp to the Commander in Chief of United Nations Command, Combined Forces Command, and U.S. Forces Korea in South Korea from May 1985 to July 1986. He attended U.S. Naval War College in Newport, Rhode Island, from August 1986 to July 1987, and then served as a Flight Commander and then Chief of Weapons and Tactics with the 363rd Fighter Wing at Shaw AFB, South Carolina, from July 1987 to February 1991 (deployed to the Middle East from October 1990 to February 1991). In that capacity, he served as a combat planner on the CENTAF planning staff during Desert Shield and flew the F-16 when Desert Storm combat commenced. Lt Col Lewis served as Chief of Fighter/Bomber assignments at the Air Force Personnel Center at Randolph AFB, Texas, from February 1991 to April 1992, and then served with the Air Intelligence Agency at Kelly AFB, Texas, from April 1992 to July 1993. He next attended Air War College at Maxwell AFB, Alabama, from July 1993 to July 1994, followed by service as Deputy Commander of the 14th Operations Group at Columbus AFB, Mississippi, from July 1994 to August 1996, flying the AT-38 Talon. Colonel Lewis was then assigned back to the Middle East as the Chief, U.S. Office of Military Cooperation, Bahrain, from August 1996 to June 1998. His career concluded as the Commander, 8th Operations Group, Kunsan AB, South Korea, where he commanded 2 squadrons of 54 F-16s and a support squadron. Colonel Lewis retired from the Air Force on January 1, 2000. He serves as an Air Force Academy Liaison Officer for the State of Pennsylvania, and was elected to the Central York School Board of Directors in 2012. In March 2018, he retired from his second career as a Captain for Southwest Airlines after 18 years of flying and became the Executive Director, Red River Valley Fighter Pilots Association. In October 1984, he married his wife Catherine Carr Lewis, they have two adult sons, Oliver and Aaron.

His Distinguished Flying Cross Citation for Valor reads:

Lieutenant Colonel Gregory W. Lewis distinguished himself by heroism while participating in aerial flight in the vicinity of the Batra Missile Production Facility, Baghdad, Republic of Iraq, on 28 January 1991. On that date, he led a devastating air strike against Scud missile production buildings, totally destroying the missile production facilities. During that strike, with complete disregard for his own personal safety, he braved heavy enemy 37 millimeter anti-aircraft artillery fire, SA-3 surface-to-air missile launches, and active enemy aircraft in the target area. As a result, the potential for enemy missile production at this facility was eliminated. The outstanding heroism and selfless devotion to duty displayed by Lieutenant Colonel Lewis reflect great credit upon himself and the United States Air Force.