The earliest known report of a UFO sighting was by Julius Obsequens, a Roman writer, in 100 B.C.. He claimed to have seen "things like ships" in the sky over Italy. Some people also believe that the Old Testament book of Ezekiel contains a reference to a UFO sighting. The Book of Ezekiel chronicles the period from about 593 B.C. to about 573 B.C., so if this is actually a UFO reference, it would pre-date the sighting by Obsequens.

I looked, and I saw a windstorm coming out of the north -- an immense cloud with flashing lightning and surrounded by brilliant light. The center of the fire looked like glowing metal, and in the fire was what looked like four living creatures.