Steven Macon Greer, born June 28, 1955, in Charlotte, North Carolina, is an American ufologist and retired physician who occupies a central position in the disclosure movement. Trained in biology (B.S., Appalachian State University, 1982) and medicine (M.D., East Tennessee State University, 1987), Greer worked for a period as an emergency-room doctor and chaired the Department of Emergency Medicine at Caldwell Memorial Hospital before retiring from medical practice in 1998. He founded two of his best-known initiatives: in 1990, the Center for the Study of Extraterrestrial Intelligence (CSETI); and in 1993, the Disclosure Project. These organizations anchor his efforts to promote what he describes as suppressed knowledge concerning UFOs, extraterrestrial intelligence, and alternative energy technologies.

Greer's public influence stems largely from his efforts to bring forward alleged eyewitnesses—military, government, and intelligence personnel—to testify about UFO phenomena at events like the Disclosure Project press conference in May 2001 at Washington’s National Press Club, where he claims over 20 such witnesses spoke. He has also produced documentaries such as Sirius (2013), Unacknowledged (2017), and Close Encounters of the Fifth Kind to disseminate his ideas and evidence. According to his accounts, Greer’s goals are not just disclosure per se but enabling a global transition away from fossil fuels via “zero point” or “quantum vacuum” energy technologies, which he alleges have been removed from public view.

CSETI under Greer's direction developed what is called the “CE-5” protocol: human-initiated contact with extraterrestrial entities through meditation, conscientious intention, and what he terms “coherent thought sequencing.” His organization has claimed thousands of reports of UFO sightings, pilot encounters, and “landing traces,” and uses teams designed to respond rapidly to alleged landing sites. Disclosure Project has proposed to grant amnesty to government officials who violate secrecy oaths in order to share classified UFO/UAP information with the public.

Many of Greer’s assertions—such as reverse engineering of alien propulsion, government conspiracies to conceal proof of ET contact, or that new energy sources have been suppressed—are alleged or claimed by him and his followers rather than accepted by mainstream science or official government agencies. These claims are controversial, partly due to lack of independently verified publicly released evidence. Critics argue that much of what Greer presents depends on anecdote, interpretation, or unverifiable documents.

Greer attributes his interest in UFO phenomena to childhood sightings and to a broader spiritual journey: before his medical career he trained in Transcendental Meditation, served in the Maharishi movement, and later incorporated meditation and Vedic studies into his UFO-related practices. These elements distinguish him from disclosure figures who approach the topic purely from a scientific or military angle.

Whether one accepts his claims or debates them, Greer matters because he has played a foundational role in shaping how modern disclosure advocates talk about UFOs or UAPs—combining claims of government secrecy, suppressed advanced technologies, spiritual practice, and alternative energy. His long-term visibility in books, film, and new media leaves little doubt that his ideas are influential to a large and active community interested in extraterrestrial intelligence and what truth, if any, might lie hidden from public view.