The Center for UFO Studies (CUFOS), renamed the J. Allen Hynek Center for UFO Studies in 1986, is a privately funded nonprofit research group based in Chicago. The astronomer J. Allen Hynek, for two decades the Air Force's scientific consultant on UFO reports, founded it in 1973. It describes itself as an international group of scientists, academics, investigators and volunteers whose purpose is "to promote serious scientific interest in UFOs" and to serve as an archive for reports, documents and publications. The ufologist James Moseley called it "the first real attempt" at a private research group genuinely dedicated to scientific UFO study.

Hynek, then chair of the astronomy department at Northwestern University, started the center in Evanston, Illinois, a few years after the Air Force closed Project Blue Book in December 1969. His 1972 book The UFO Experience had introduced the "close encounters" classification, and CUFOS gave his push for case files, field investigation and scientific participation a home outside government. In November 1976 it launched the International UFO Reporter, its main news and feature magazine until 2012. It also published the Journal of UFO Studies, in an original series from 1979 to 1983 and a new series from 1989 to 2006. Both are now free to read online.

The center also took on UFOCAT, a computer catalog of sighting reports begun by the psychologist David Saunders during the Air Force-funded University of Colorado study run by the Condon Committee. Saunders gave his version to CUFOS in 1976. It was maintained until 1982, set aside on tape when mainframe costs grew too high, and revived after Donald Johnson obtained a copy in 1990; the 2023 edition holds more than 300,000 entries, over 192,000 of them primary reports. After Hynek passed away in 1986, the center took his name, and Mark Rodeghier, whom Hynek had chosen as his successor, became scientific director, the post he still holds. Its board includes Jerome Clark, Michael Swords, Thomas E. Bullard and the archivist David Marler.

CUFOS acquired the case files of the National Investigations Committee on Aerial Phenomena as that group dissolved around 1980. In November 2020 its case files, including Hynek's personal files, moved to New Mexico, where the National UFO Historical Records Center curates them on the center's behalf; in 2026 the Pentagon's All-domain Anomaly Resolution Office moved to buy subscription access to that archive's pre-1990 records. UFOCAT has also entered the scientific literature. In an October 2025 Scientific Reports paper, Stephen Bruehl and Beatriz Villarroel drew daily UAP report counts from the "comprehensive UFOCAT database maintained by the Center for UFO Studies" and compared them with transients on 1950s Palomar sky-survey plates, noting that the reports had not been checked for validity.

The center still publishes historical features online, including a series revisiting 1952 cases such as the Flatwoods sighting and the Tremonton film, and a review of 2025's UAP events. More than five decades after Hynek founded it, CUFOS remains a small research group whose catalog, journals and transferred files supply much of the documentary base for historical study of American UFO reports.