Hilary Evans (1929–2011) was a British researcher, author, and archivist known for his work on UFOs and other paranormal subjects. Educated at Cambridge and Birmingham Universities, he began his career in advertising before co-founding the Mary Evans Picture Library with his wife in 1964. This library served as an archive for historical illustrations. Evans was also a co-founder of the Association for the Scientific Study of Anomalous Phenomena in 1981. His research into the paranormal led him to propose the Psychosocial Hypothesis, suggesting UFO experiences are culturally influenced visions.

Throughout his career, Evans authored and edited numerous books exploring topics such as prostitution, paranormal phenomena, UFOs, altered states of consciousness, and extraordinary social behaviour. His work in the field of UFOlogy was noted by critics, with some acknowledging his informed perspective while others pointed to a perceived lack of scientific rigor and a tendency to accept paranormal claims at face value. Despite criticisms, his contributions to the study of anomalous phenomena and his extensive archival work remain significant.

Hilary Evans dedicated a significant portion of his work to investigating UFOs and a wide range of paranormal phenomena. He is noted for developing the Psychosocial Hypothesis concerning UFO sightings. This theory posits that many reported UFO experiences can be understood as visionary encounters shaped by cultural contexts and expectations, rather than necessarily indicating extraterrestrial visitation. Evans explored this and related concepts in several of his books, examining the intersection of societal beliefs and individual perceptions of the extraordinary. His research encompassed apparitions, spirits, and other anomalous experiences, seeking explanations within the framework of human psychology and cultural history.

Beyond his research into the paranormal, Hilary Evans was a co-founder of the Mary Evans Picture Library in 1964, alongside his wife Mary. This institution became a significant archive of historical illustrations, serving researchers and creatives. Evans also authored and edited a substantial body of work. His published titles covered diverse subjects, including a history of prostitution, various aspects of the paranormal, UFO phenomena, and altered states of consciousness. He collaborated with other researchers and editors on several anthologies, contributing to the discourse on anomalies and their historical and cultural contexts.