Rex Gilroy (born November 9, 1943) is an Australian who has written articles and self-published books on cryptids and unexplained or speculative phenomena.
His work has focused on yowie reports, 'out of place' animals, UFOs, and propositions regarding a 'lost' Australian civilization.
He has contributed to, or been the subject of, several articles, in speculative media such as Nexus magazine and in Australian newspapers.
He is the author and publisher of several books, the first of which appeared in 1986.
He has documented over 3000 reports relating to yowies.
His eclectic career has seen field research into butterflies and anthropology, but he remains most notable for his controversial searches for the recently extinct thylacine, moas, alien big cats, the long-extinct megalania, or the source of the yowie legend.