David Michael Jacobs (born 1942) is an American historian who taught twentieth-century American history and popular culture at Temple University in Philadelphia for more than three decades. He began as a historian of the UFO controversy and became one of the best-known alien abduction researchers of the 1980s and 1990s. Working with people who believed they had been taken, he used hypnosis and concluded that the abductions serve an alien breeding program. Those conclusions, and the methods behind them, have drawn sustained criticism from psychologists, scientists and skeptics.

Jacobs studied at UCLA and earned a master's degree and, in 1973, a doctorate in history at the University of Wisconsin–Madison, with a dissertation on how authorities handled UFO reports. Indiana University Press published a revised version as The UFO Controversy in America in 1975. From 1977 he taught a Temple course on UFOs in American society, in which he described the Air Force-funded Condon Committee as having worked to discount sightings. The course drew steady enrollment and divided his colleagues. The university kept it on grounds of academic freedom, but Jacobs said he was twice passed over for promotion to full professor.

After observing the hypnosis sessions of the artist and researcher Budd Hopkins, Jacobs began conducting his own in 1986. Secret Life (Simon & Schuster, 1992), with an introduction by the Harvard psychiatrist John Mack, drew on hypnosis interviews with about 60 people and argued that aliens were taking human sperm and eggs to produce hybrids. The Threat (1998) argued that the program's goal was to integrate hybrids into human society. In 2000 he edited the collection UFOs and Abductions for the University Press of Kansas, and Walking Among Us (2015) argued that hybrids were already living among people. As director of the International Center for Abduction Research, he said he had worked with about 150 people who reported abductions.

Critics have focused on his method. Martin Gardner noted that Jacobs had no training in psychology, psychiatry or hypnotherapy. The psychologist Susan Clancy argued that hypnosis can lead subjects to build false memories and that sleep paralysis explains many reports, while Carl Sagan had earlier attributed such reports to mistaken identity and faulty memory. The planetary scientist William Hartmann said most scientists give little credence to reports drawn out under hypnosis. The folklorist Thomas Bullard found no clear precedent for the hybrid-child episodes that Hopkins and Jacobs popularized, and Mack rejected the dire reading Jacobs gave the same kind of accounts. Jacobs has replied that many abductees describe being fully awake, has said Clancy's book is factually incorrect, and has conceded that confabulation is a problem and the evidence is "weak."

Jacobs told his alumni magazine in 2021 that he had stopped his abduction research, but his ideas remained in circulation in 2026. Posts on X quoted his hierarchy of insect-like leaders, tall and short Greys and hybrids, and podcast guests traced the origins of modern abduction research through Hopkins and Jacobs. With Hopkins, he was instrumental in popularizing the idea of a systematic alien breeding program, and his books remain both its fullest statement and a standard target for critics of hypnosis-based abduction research.