Largest civilian UFO investigative group

The largest civilian UFO/UAP research group is the Mutual UFO Network (MUFON), a non-profit organization based in Cincinnati, Ohio, USA. It was founded on 31 May 1969 (as the Midwest UFO Network) by college professor Allen Ukte and engineer Walter Andrus (both USA). As of 2024, the organization had a reported membership of more than 4,000 and an annual revenue of $637,000.

MUFON was founded to serve as a grassroots UFO investigation network. Its founding members were dissatisfied with earlier organizations such as the National Investigations Committee On Aerial Phenomena (NICAP) and Aerial Phenomena Research Organization (APRO), which operated in a more centralized way. Following the publication of the Scientific Study of Unidentified Flying Objects (better known as the "Condon Report") in 1968, which largely dismissed the UFO phenomenon, many in the community felt they needed a new approach to information gathering. MUFON's membership and the scope of its interests quickly spread beyond the midwestern United States, so the name was changed to "Mutual UFO Network" in 1973.

Since the early 1970s, MUFON has run training programs designed to teach best practices for investigators, improving the quality and consistency of their activities around the world. The reports these investigators write, as well as witness statements collected directly from the public, are stored in the organization's Case Management System. As of 2024, this database had more than 140,000 witness statements and case reports.