Thomas Lacy was born on January 5, 1927, in Long Beach, Mississippi. He graduated from Long Beach High School in 1945, and then attended Perkinston Junior College for a year before attending Maryville College, Tennessee, where he graduated with a bachelor's degree in English in 1950. He entered Officer Candidate School on December 29, 1950, and was commissioned a 2d Lt in the U.S. Air Force on June 22, 1951. Lt Lacy next completed pilot training and was awarded his pilot wings at Williams AFB, Arizona, in October 1952, and then F-86 Sabre Combat Crew Training in January 1953. He deployed to Korea in February 1953, and flew 67 combat missions as an F-86 pilot with the 67th Fighter-Bomber Squadron before returning to the U.S. in November 1953. His next assignment was as an F-86 and F-100 Super Sabre pilot with the 531st Fighter-Bomber Squadron, 435th Fighter Day Squadron, and 476th Fighter Day Squadron at George AFB, California, from December 1953 to January 1959, followed by service as an RF-84 Thunderflash and RF-101 Voodoo pilot with the 38th Tactical Reconnaissance Squadron at Phalsbourg AB, France, from January 1959 to May 1960. Capt Lacy served with the 66th Tactical Reconnaissance Wing at Laon AB, France, from May 1960 to July 1962, and then as an F-105 Thunderchief pilot with the 354th Tactical Fighter Squadron at George AFB from August 1962 to August 1964. Maj Lacy attended the Marine Corps Command and Staff College at Quantico, Virginia, from August 1964 to May 1965, and then served with the 355th Tactical Fighter Wing at McConnell AFB, Kansas, from June to August 1965. His next assignment was on the staff of Headquarters 2nd Air Division at Tan Son Nhut AB, South Vietnam, from August 1965 to March 1966, followed by service on the staff of Headquarters 7th Air Force, also at Tan Son Nhut, from April to August 1966, during which time he flew 8 combat missions in the F-105. Col Lacy served on the staff of Headquarters Pacific Air Forces at Hickam AFB, Hawaii, from August 1966 to July 1969, and then deployed to Southeast Asia in July 1969, serving as Commander of the 531st Tactical Fighter Squadron at Bien Hoa AB, South Vietnam, from August 1969 to January 1970. During this time he flew 227 combat missions in the F-100 and A-37 Dragonfly. His next assignment was as Deputy Commander for Operations of the 3rd Tactical Fighter Wing at Bien Hoa AB from January to July 1970, followed by Air War College at Maxwell AFB, Alabama, from August 1970 to July 1971. Col Lacy served as Director of Operations and then Vice Commander of the 347th Tactical Fighter Wing (later redesignated the 366th Tactical Fighter Wing) at Mountain Home AFB, Idaho, from July 1971 to January 1973, and then as Vice Commander of the 474th Tactical Fighter Wing at Nellis AFB, Nevada, from January to March 1973. He then deployed with the 347th Tactical Fighter Wing to Takhli Royal Thai AFB, Thailand, from March to March 1974, during which time he flew 48 combat missions in the F-111 Aardvark. Gen Lacy next served as Deputy Commander of the Field Command of the Defense Nuclear Agency at Kirtland AFB, New Mexico, from March 1974 to September 1975, and then as Commander of the Field Command from September 1975 until his retirement from the Air Force on November 1, 1977. After his retirement from the Air Force, Tom devoted a large portion of time to the cause of former prisoners of war and those still missing in action. Thomas Lacy died on October 15, 2010.

His Legion of Merit Citation reads:

Colonel Thomas E. Lacy distinguished himself by exceptionally meritorious conduct in the performance of outstanding services to the United States as Commander, 474th Tactical Fighter Wing and as Commander, 347th Tactical Fighter Wing, Takhli Royal Thai Air Force Base, Thailand, from 14 March 1973 to 7 March 1974. During this period, the exemplary ability, diligence, and devotion to duty of Colonel Lacy were responsibility for the Wing's successful launching of 5,027 combat sorties, which equated to 100 percent of the fragged tasking by higher headquarters. Upon termination of United States bombing in Cambodia on 15 August 1973, Colonel Lacy's personal endeavor and demands for quality maintenance and operations enabled the 347th Wing to transition smoothly to a peacetime training environment. This was achieved while still maintaining the required combat capabilities, despite personnel turbulence evolving from conversion of the unit from temporary duty to permanent change of station status. The superior initiative, outstanding leadership, and personal endeavor displayed by Colonel Lacy reflect great credit upon himself and the United States Air Force.