Thornton D. "TD" Barnes is an American retired electronics engineer, author and veterans' organizer who describes himself as a former member of the CIA's special projects team at Area 51. He is president of Roadrunners Internationale, an association of CIA, Air Force and contractor personnel from the U-2 and A-12 spy-plane programs at Groom Lake, Nevada, and his biography on its website also lists him as director of the Nevada Aerospace Hall of Fame. In recent years he has used that background to argue against claims that the base ever handled alien spacecraft.

According to that biography, Barnes spent about ten years in the U.S. Army, serving as an intelligence specialist in Korea and training in Nike and HAWK surface-to-air missile electronics before an injury during officer candidate school ended his military career. He then worked as an electronics engineer at the Beatty station of NASA's High Range tracking network in Nevada, supporting flights of the X-15, XB-70, lunar landing research vehicles, lifting bodies and Blackbird aircraft, and spent a year at Wright-Patterson Air Force Base testing the Apollo capsule.

Barnes says he was then recruited to Groom Lake, where he worked under a code name on projects including the CIA's A-12 OXCART and the Air Force's exploitation of Soviet MiG fighters, programs he credits with inspiring the Navy's Top Gun school and the Air Force's Red Flag exercises. He also says he was loaned to NASA's NERVA nuclear-rocket program at Jackass Flats. He described the MiG projects in his 2014 book MiGs Over Nevada, and as head of the Roadrunners he has made recording members' recollections, including for oral-history projects, a priority.

His UFO-related profile is skeptical. In remarks from 2021 later circulated by researcher Joe Murgia, Barnes called the UFO research funded at Senator Harry Reid's urging a hoax and attributed the 2004 Navy "Tic Tac" encounters to testing of radar spoofing and electronic warfare. On the Danny Jones Podcast in July 2026, he argued that Bob Lazar's account could not be true because no one entered Area 51 without being cleared and recorded, and said craft able to reach Earth would not be crashing. He has also said that Roswell was nothing but balloons and, in 2026, that most of Annie Jacobsen's 2011 book Area 51 was made up and that her source for its Roswell story had told it as a joke.

On Roswell, Barnes's view matches the Air Force's 1990s conclusion that the debris most likely came from a Project Mogul balloon train. Murgia has said Barnes claims more than he can back up, noting that the Tic Tac case was examined for a Pentagon-funded program in 2009 and that aviators described seeing the object directly. Speaking on the record as a self-described Groom Lake veteran, Barnes remains one of the most direct insider voices disputing accounts of recovered alien craft at Area 51.