User
Well..."angel" is (over-simply) the Latin translation of a Hebrew word that means "messenger", so any pre-Jewish writing that mentions "angels" would be, perhaps, ambiguous because any supernatural "messenger" in a foreign (non-Hebrew) language might be deemed an "angel", a "spirit", a "demon" or a "god" (or something else). We can say (from the strictest point of view) that the concept of "angels" first appeared in Judaism (or Yahwism).
However, the word "cherubim" - a particular type of Biblical angel - is witnessed in pre-Jewish writings and art:
http://en.wikipedia.org/wiki/Cherub#Origins
and the Biblical description to a great extent matches the Babylonian/Phoenician images.
?
In Zoroastrianism there were angelic beings called Ahuras.
Anonymous
The Enuma Elish, though the term "angels" is not used specifically. Any "beings that come from the heavens" should qualify though.