Berossus or
Berosus (; name possibly derived from , "
Bel is his shepherd"; ) was a
Hellenistic-era
Babylonian writer, a priest of Bel
Marduk and
astronomer who wrote in the
Koine Greek language, and who was active at the beginning of the 3rd century BC. Versions of two excerpts of his writings survive, at several removes from the original.