Knud Valdemar Gylding Holmboe (April 22, 1902 Horsens Denmark - October 13, 1931 Aqaba Jordan) was a Danish journalist and explorer who converted to Islam after travels in North Africa. Born in Horsens he travelled to Morocco as a young man, in order to familiarize himself with Islam and learn the Arabic language.
Upon his conversion, Holmboe changed his name to Ali Ahmed. Driving through the Sahara in an old Chevrolet, he left the beaten track to discover the communities and landscape of the desert. Knud Holmboe was shocked to observe European violence against the indigenous populations of the North African colonies. Based on these travel experiences, he produced a book in 1931 entitled Desert Encounter (Danish: Ørkenen Brænder, lit. "the desert is on fire"), in which he condemned the colonial overseers. The book was immediately banned in Italy. The Italian colonial powers were outraged at the suggestion that the Muslim population of Libya was being subjected to genocide.
After completing his book, Knud Holmboe started on his hajj to the city of Mecca.
In circumstances that were never fully explained, Knud Holmboe was murdered just south of Aqaba (in modern Jordan) on October 13, 1931. While it has been speculated that Italian intelligence ordered the murder, this claim has never been verified.